ABSTRACT During the first months of life, breast milk oligosaccharides (HMOs) stimulate development of the gastrointestinal tract in newborns and young infants; they modulate its metabolism and transport capabilities. Additionally, they exert prebiotic and antimicrobial activities and contribute to the development of the resident intestinal microbiota with a predominance of Bifidobacterium and Bacteroides and protect from colonization and infections by enteropathogens (bacteria, virus or parasites). It is highly probable that their activities extend beyond infancy and persist into adult life. HMOs stimulate the development of the innate and adaptive immune systems and decrease the risk of atopy/allergy. Their intake has been associated with a degree of protection against as necrotizing enterocolitis among premature infants. HMOs contribute to the long term adaptation and protection of newborn infants to unfavorable conditions of their environment and in this way may contribute to protect breastfed infants from type 1 diabetes and obesity.

RESUMEN Durante los primeros meses de vida, los oligosacáridos de la leche materna (HMOs) aportados por la leche materna participan en procesos asociados con la maduración de tejidos y sistemas del tubo digestivo, modulan algunos de sus procesos metabólicos y ejercen efectos prebióticos y antimicrobianos. Otros efectos estudiados son su contribución a la instalación, desarrollo y estimulación de la microbiota residente con predomino de Bifidobacterium y Bacteroides, con efectos protectores frente a posibles colonizaciones o patologías por enteropatógenos (bacterianas, virus o parásitarias) que pueden actuar nivel local en el tubo digestivo, pero también pueden influir a nivel sistémico. Los HMOs modularían el desarrollo de la inmunidad innata y adaptativa, y probablemente previenen el desarrollo de fenómenos de atopia/alergia. Una patología propia de la etapa neonatal de los prematuros es la enterocolitis necrosante y algunos HMOs podrían disminuir el riesgo de su manifestación. Las actividades de los oligosacáridos de la leche materna contribuyen a la adaptación del lactante a los desafíos que plantea su entorno incluyendo la prevención de algunas patologías en edades posteriores, como es el caso de la diabetes tipo 1 y la obesidad.

ABSTRACT Human milk oligosaccharides (HMOs) are a family of some 200 different molecules synthesized by the mammary gland. At the core is a molecule of lactose, which is linked by different enzymes to glucose, galactose, n-acetyl galactosamine, fucose or sialic acid. These linkages and their different spatial orientation generate, besides the possibilities of numerous chemical structures, the potential for different spatial isomers. The concentration of HMOs in human milk depends on pregnancy and breastfeeding duration. They are highest in colostrum (± 25 g/L) and decrease over time to half this initial level. Maternal genetics modifies the concentration and profile of some oligosaccharides. For example, the FUT2 gene codifies the synthesis of fucosyltransferase 2 (FUT2) whose activity generates the secretor status for antigens of the ABO(H) blood group in organic fluids (saliva, milk, tears, semen) among 75-85% of the carriers of the trait. The absence of activity of the FUT2 gene conditions the non-secretor status (15-25% of women). The FUT3 gene regulates the activity of the fucosyltransferase 3 (FUT3) that is associated with the Lewis blood group. Traces of HMOs (1%) are absorbed in the intestinal tract, however, they exert important systemic effects even at low concentrations.

RESUMEN Los oligosacáridos de la leche materna (HMOs) son unas 200 moléculas distintas sintetizadas y secretadas por la glándula mamaria a partir de lactosa a la que diversos enzimas unen monosacáridos simples (glucosa, galactosa, n-acetil galactosamina, fucosa y ácido siálico). Estas uniones y sus diferentes orientaciones espaciales generan una gran diversidad de estructuras químicas y de funcionalidades. La concentración de los HMOs es mayor en el calostro (± 25 g/L), está relacionada con la duración del embarazo y la lactancia: disminuyen progresivamente hasta la mitad de los niveles iniciales. La genética materna influye en el perfil de algunos HMOs; el gen FUT2, que codifica la síntesis de la fucosiltransferasa 2 (FUT2) condiciona el llamado carácter secretor en 75-85% de las mujeres y hace que los antígenos del grupo ABO(H) sean secretados en los líquidos orgánicos (saliva, lágrimas, semen). La ausencia de actividad del gen FUT2 condiciona el carácter no-secretor (15-25% de las mujeres). La actividad del gen FUT3 condiciona la actividad de la fucosiltransferasa 3 (FUT3) que se asocia con el grupo sanguíneo Lewis+ mientras que su ausencia caracteriza a los portadores como Lewis 0. Los HMOs son absorbidos a nivel del intestino como trazas (1%) pero incluso en esas cantidades ejercerían efectos sistémicos.

Abstract: The mammary gland and maternal milk are the product of millions of years of evolution that resul ted in an optimal composition that sustains the growth and development of newborns and infants. Maternal milk supports the growth, adaptation and survival of this immature organism. Recent studies have detected 1606 different proteins in human milk, most of them synthesized in the acini of the glandular tissue while others originate from distant organs such as the lymphoid tissue and the digestive tract. Maternal milk enzymes modify its proteins and liberate peptides with antimicrobial, antihypertensive or stimulatory activities. This proteolytic activity occurs at specific sites in peptide chains. To prevent the extemporaneous activation of these proteolytic enzymes, that would result in inflammatory processes, maternal milk also contains inhibitory peptides that together with the stimulatory peptides conform a complex regulatory system. Some enzymes in maternal milk main tain their activity in the gastrointestinal tract of infants and compensate for the decreased activity of digestive tract enzymes in newborns. Thus, the milk enterokynase stimulates the release of pancreatic proteases as it induces the liberation of cholecystokynin/pancreozymin. The bile salt-activated lipase of human milk is activated in the duodenum by the infants’ bile salts and partially compensates for the low levels of pancreatic lipase in newborns. These milk enzymes probably contribute to the nutrition of premature infants as they increase the availability of amino acids and peptides in their upper gastrointestinal tract; furthermore, as their intestinal epithelium is more permeable to peptides and partially digested protein this may help induce immune tolerance. The most relevant issues in the physiology and composition of the maternal milk are presented in this review.

Resumen: La glándula mamaria y la leche materna son el resultado de millones de años de una evolución que llevó a una composición óptima para el crecimiento y desarrollo de recién nacidos y lactantes; la leche materna favorece el crecimiento, la adaptación y la supervivencia de su organismo y de sus órganos inmaduros. Análisis recientes han demostrado en ella la presencia de 1606 proteínas que en su mayoría son sintetizadas en los acinos de la glándula mamaria aunque otras proteínas y péptidos provienen de órganos como el sistema linfático y el aparato digestivo. La composición de la leche materna incluye enzimas que modifican sus proteínas y originan péptidos antimicrobianos, antihipertensivos y estimuladores del metabolismo. Esta actividad proteolítica actúa en sitios específicos de las cadenas peptídicas de la proteína de la leche. La activación extemporánea de estos enzimas en los acinos es regulada por péptidos inhibidores y activadores que previenen procesos inflamatorios. Algunos enzimas de la leche actúan en el tubo digestivo de recién nacidos y lactantes y complemen tan la menor concentración y actividad de sus propios enzimas digestivos. Así, la enteroquinasa de la leche estimula la liberación de enzimas pancreáticos (mediada por el estímulo de la colecistoquinina-pancreozimina); la lipasa activada por las sales biliares complementa la baja producción de lipasa pancreática. Estas actividades probablemente facilitan la nutrición de los prematuros, cuyo tubo di gestivo es más permeable a las proteínas parcialmente hidrolizadas y cuyas actividades enzimáticas y factores defensivos locales no han alcanzado su plena madurez. Esto también puede estimular en ellos la tolerancia inmunológica. En este artículo se presentan los aspectos fisiológicos relevantes de la leche materna, y los avances en el conocimiento de su composición, para el cabal conocimiento del pediatra de esta importante materia.

Probiotics have been defined as live microorganisms which, when ingested in adequate numbers, confer health benefits to the host. They are currently consumed without any age restrictions and adverse effects such as sepsis, a marker of the risk of invasion of the bloodstream, are extremely infrequent. However, some health professionals express doubts about probiotics being truly innocuous. This review discusses the incidence of sepsis secondary to probiotics use, mainly lactobacilli and bifidobacteria, evaluated through molecular biology or classic culture techniques, showing that sepsis in large numbers of individuals along decennia is extremely low, of the order of 0,02% en some centers or as low as 1 case/million population in France. These data are important considering the use different species and strains of these microorganisms. Few studies which have reported other adverse effects but many of these have problems with their design that cast doubt about the validity of their results. On the contrary, it has been shown that probiotic microorganisms exert positive stimulatory effects on innate and acquired immunity, with decrease of the manifestations of atopy and eczema. These positive effects are further evidenced by the beneficial effects of many species of probiotics in preventing necrotizing enterocolitis in patients as functionally labile as premature-born babies.

Los probióticos son microorganismos vivos que cuando son administrados en cantidades adecuadas confieren beneficios a la salud del huésped. Su empleo es muy amplio en todas las edades, y los episodios adversos asociados con ellos, incluyendo casos de sepsis, que hagan suponer un riesgo real y manifiesto de invasión del torrente sanguíneo o algún tipo de contagio son muy infrecuentes. Sin embargo, algunos profesionales de la salud manifiestan dudas respecto de su inocuidad. Esta revisión revela que la incidencia de sepsis por probióticos, principalmente lactobacilos y bifidobacterias, evaluada en casuísticas numerosas a lo largo de decenios usando métodos de biología molecular o cultivos, es muy baja: del orden de 0,021% en algunas estadísticas y podría llegar hasta 1 caso/1.000.000 de habitantes. Estos datos son importantes teniendo en cuenta el empleo masivo de diversas especies y cepas, sin restricciones de ninguna especie y en todas las edades. Algunos estudios que comunican otros efectos adversos tienen problemas de diseño que ponen en duda su validez. Por el contrario, se ha demostrado que los probióticos ejercen efectos positivos estimulando la inmunidad innata y adquirida, en el tratamiento de la atopia y eccema y en la prevención de la enterocolitis necrosante en sujetos tan vulnerables como los prematuros.

Lactobacilli are normal inhabitants of the human intestine. They are also present in maternal milk, where Lactobacillus reuteri was first described. This confirms that maternal milk transfers components of the maternal microbiota to the offspring. L. reuteri ATCC 55730 decreases the intensity and duration of infantile colic defined as episodes of strident crying for at least 3 hours, 3 times a week during 3 months. Its etiology is unknown but recent evidence shows that affected infants harbor less Iactobacilli and more Bacteroides in their feces. In 2008 it was shown that this strain carries plasmidia that could transfer resistance to antibiotics. For this reason L. reuteri it was cured of these factors and this resulted in L. reuteri DSM 17938 which is devoid of them; tests in vitro, in laboratory animals and in humans demonstrated that both strains are equivalent. The effect of L. reuteri in infantile colic may be explained by its blocking at the level of the dorsal ganglia of the spinal chord of the transmission to the central nervous system of afferent pain stimuli. L. reuteri has effects on gastroesophageal reflux probably through the acceleration of gastric emptying and it decreases the incidence and severity of necrotizing enterocolitis. Other positive effects are related to chronic constipation and acute diarrhea. L. reuteri synthesizes a molecule with intense bactericidal activity, β-hidroxy propenal o reuterin from glycerol, which may explain some of its effects. Lactobacillus rhamnosus GG ATCC 53103 is probably the probiotic that has been studied the most and for a longer period. It shortens the duration and it decreases the number of evacuations in acute diarrhea as well as the duration and frequency of vomiting. It also induces improvements of antibiotic associated diarrhea and of upper respiratory infections. The positive effects of Lactobacillus GG may be due to the stimulation of innate and adaptive immunity and to the activation of macrophages and of NK lymphocytes. One of its effects refers the response its administration induces in infants with atopy/eccema. Some studies have demonstrated that the severity and extent of the lesions is decreased after Lactobacillus GG administration, that may persist for some years after its administration has been ended. Lactobacillus GG also exerts positive effects on conditions such as the irritable bowel syndrome through mechanisms that are not known with certainty.

Los lactobacilos son habitantes normales de las mucosas de los seres humanos; también están presentes en la leche materna. Lactobacillus reuteri fue descrito en la leche de una madre peruana, lo que confirma que estas bacterias son parte de la microbiota que las madres transfieren a sus hijos. El cólico infantil son episodios de llanto excesivo, estridente, por a lo menos 3 horas 3 veces por semana y por a lo menos 3 meses. L. reuteri ATCC 55730 demostró disminuir su intensidad y duración. La etiología del cólico se desconoce pero en las heces de los lactantes afectados se han demostrado disminuciones de los lactobacilos y aumentos de Bacteroides. En 2008 se demostró que L. reuteri ATCC 55730 era portador de plasmidios capaces de resistencia a antibióticos por lo que fue "curado" de estos factores y resultó una nueva cepa, denominada DSM 17938; pruebas in vitro y en animales mostraron su inocuidad y ensayos en humanos revelaron que ejerce las mismas propiedades benéficas que la cepa original. El efecto de L. reuteri en el cólico infantil puede estar relacionado con su capacidad de bloquear en los ganglios dorsales de la medula espinal la transmisión de estímulos a los centros cerebrales superiores. El efecto antirreflujo de L. reuteri se debería a la aceleración del vaciamiento gástrico. Ambas cepas de esta bacteria disminuyen la progresión, morbilidad y mortalidad de la enterocolitis necrosante. Otros efectos en la constipación crónica y la duración de la diarrea aguda de distintas etiologías. L. reuteri sintetiza una molécula, el β-hidroxipropenal o reuterina, con actividad antibacteriana. Lactobacillus rhamnosus GG ATCC 53103 es probablemente el probiótico más estudiado; acorta la duración de la diarrea aguda, disminuye el número de evacuaciones y la duración de los vómitos e induce mejorías de la diarrea asociada con los tratamientos antibióticos; y disminuiría la intensidad de las infecciones respiratorias altas. Sus efectos se deberían a la estimulación de las inmunidades innata y adquirida y de la activación de los macrófagos y los linfocitos NK. Un efecto notable y discutido de L. ramnosus GG se refiere a sus efectos en la atopia cutánea, ya que disminuiría la extensión e intensidad de sus síntomas, incluso más allá de su administración. También ejercería efectos sobre cuadros funcionales gastrointestinales como el síndrome del intestino irritable, por mecanismos aun no elucidados.

Bifidobacterium animalis ssp lactis Bb12 is a probiotic strain that has received considerable attention from the scientific community. It has tolerance to higher temperatures and lower, acidic pH than other bacteria. When administered for 12 months to infants and children together with S. thermophilus this was associated with lower incidences of acute diarrhea. Studies in different countries and with different experimental designs confirmed these results. It was also shown that its administration did not interfere the growth or the normal weight gain of the children. Bifidobacterium animalis ssp lactis Bb12 was associated with decreases of the fecal excretion of rotavirus during episodes of diarrhea, a fact that represents an epidemiological benefit. Bifidobacterium animalis ssp lactis Bb12 exerts positive effects on manifestations of atopy/eczema, with decreases of the parameters of inflammation such as CD4 in blood serum and eosinophil protein X in urine. This was associated with changes in the extension and severity of the skin lesions. No modifications of the normal growth parameters were observed when Bifidobacterium animalis ssp lactis CNCM I-3446 was given. Administration of Bifidobacterium animalis ssp lactis Bb12 is associated with higher levels of fecal sIgA and calprotectin, which are considered parameters of immune responses and ofthe capacity to launch inflammatory responses. The statements made by some groups that infants under 4 months of age who are not breastfed should not receive probiotics have weak support if it is considered that maternal milk contains a large number and variety of strains of bacteria which may be considered as probiotics. These may not only protect from acute diarrhea but also from upper respiratory infections. Although cases of septicemia due to probiotic have been reported these represent an infinitely small proportion of the total numbers of consumers. No outbreaks have been reported that would point to invasive properties in a strain. It is not advisable to administer any living bacteria to individuals in shock or with innate or severe defects of immunity. However, carriers of HIV or patients with AIDS benefit from probiotic agents. A study carried out in Chile showed that although without evident clinical benefits L. rhamnosus HN001, significantly increased fecal sIgA as a manifestation of improved mucosal defense in the digestive tract.

Bifidobacterium animalis ssp lactis Bb12 es una de las cepaBifidobacterium animalis ssp lactis Bb12 es una de las cepas probióticas más estudiadas. Posee ventajas que la hacen útil para el uso industrial: tolerancia a ambientes ácidos y a temperaturas superiores a las de los demás probióticos. En un estudio de 12 meses Bifidobacterium animalis ssp lactis Bb12 fue administrada por un año asociada con S. thermophilus y se observó que los niños experimentaron menos episodios de diarrea aguda. Estudios con seguimientos de distinta duración y diseño refrendaron estos resultados y su administración no ejercía influencias negativas en el crecimiento. Esta bifido-bacteria inducía disminuciones de la excreción de rotavirus durante episodios de diarrea, lo que disminuye la posibilidad de contagios. Bifidobacterium animalis ssp lactis Bb12 ejerce efectos positivos sobre las manifestaciones de atopia como el eccema con el descenso de marcadores de inflamación tales como CD4 en el suero y de la proteína X de los eosinófilos en la orina; y mejorías de las alteraciones de la permeabilidad. Estudios con Bifidobacterium animalis ssp lactis CNCM I-3446 administrada con ARA y DHA mostraron alteraciones de los parámetros de crecimiento y bioquímicos en lactantes y preescolares en seguimientos entre 14 y 119 días. La administración de Bifidobacterium animalis ssp lactis Bb12 junto con inmunizaciones se asociaba con niveles más elevados de sIgA específica anti-poliovirus y de calprotectina, cuyos niveles estarían asociados con los de esta inmunoglobulina. Se ha sostenido que no existe justificación para administrar probióticos a menores de 4-6 meses no amamantados, el hecho que la leche materna los proporciona en cantidad y variedad apoya las posibles ventajas de su administración. Los probióticos protegerían no sólo de infecciones del tracto gastrointestinal sino también de las respiratorias altas. Hay casos aislados de sepsis en individuos con diversas afecciones, pero la proporción de afectados es mínima. No se han comunicado brotes epidémicos que indicarían cepas probióticas con capacidades invasoras. Probablemente no es aconsejable administrarlos a sujetos en shock o con defectos de la función de barrera intestinal. Los portadores de VIH y los pacientes con SIDA experimentan mejorías al recibir probióticos. En un estudio en Chile se demostró que aunque sin efectos clínicamente evidentes, administrar L. rhamnosus HN001 produjo aumentos del la IgA secretoria fecal, que representa un aumento de las defensas del tubo digestivo.

Probiotics are live microorganisms which, when ingested in adequate numbers, confer health benefits to the host. They originate mostly from the colonic and vaginal microbiota of humans although a number of strains originate from the environment. The human fetus is colonized after birth by bacteria of maternal fecal and vaginal origin and by microorganisms from the environment. Maternal milk contains a varied microbiota, mainly lactobacilli and bifidobacteria. After weaning the resident microbiota becomes more complex and by 2 years of age it is composed of some 1500 species with 1014 microorganisms. During the colonization of the digestive tract of premature infants low birth weight, immaturity of the defenses and artificial feeding may lead to necrotizing enterocolitis. This inflammatory condition involves mainly the terminal ileum and the colon and may result in necrosis and perforation of the wall with subsequent peritonitis. Anoxia and abnormal colonization are important associated factors. Probiotic administration is associated with a decreased risk of this condition and decreases of its morbidity, mortality and sequelae if the treatment is started early. The positive effects are associated with more than one species of probiotics. The risk of septicemia associated with probiotics has been widely discussed. Studies in Helsinki, Finland, demonstrated that the results of comparing the frequency and etiology of septicemia during the 10 years after the introduction of probiotics with the results in the 10 years previous to their introduction were not different. Septicemia due to probiotics is infrequent and most cases are associated with extreme prematurity, failure of the intestinal barrier function, heart valve disease, severe shock and congenital immune deficiencies; patients with these conditions should be closely watched if they consume probiotics. However, patients with HIV and AIDS benefit from the consumption of these microorganisms. It has nor been demonstrated that probiotics play a role in the genesis of obesity.

Los probióticos son microorganismos vivos que al ser ingeridos en cantidades adecuadas confieren beneficios para la salud del huésped. Provienen mayormente de la microbiota del colon de seres humanos aunque algunas cepas provienen del ambiente. El colon del recién nacido es colonizado durante el parto por bacterias provenientes de las microbiotas fecal y vaginal maternas, del ambiente y por lactobacilos y bifidobacterias de la leche materna. Con el destete esta microbiota se hace compleja y desde los 2 años de edad alberga unas 1500 especies y recuentos de 1014 bacterias. En la colonización del tubo digestivo de los prematuros el bajo peso de nacimiento, la inmadurez de las defensas y la alimentación artificial cuando la madre es incapaz de amamantar, llevan en una proporción de los casos a la enterocolitis necrosante, que puede afectar la pared ileal o colónica, con perforación y peritonitis en algunos prematuros. La colonización microbiológica anormal jugaría un papel importante. Los probióticos disminuyen el riesgo de este cuadro y su morbilidad y mortalidad en los casos iniciales y de intensidad media. Estos efectos positivos son causados por diferentes probióticos. El riesgo de septicemia asociado con los probióticos ha sido ampliamente discutido. Estudios en Finlandia no han demostrado que durante 10 años de su consumo masivo se produjeran aumentos de su incidencia ni cambios de su etiología en comparación con resultados previos a su introducción. Las septicemias han sido detectadas principalmente en individuos con graves alteraciones de su salud, pérdida de la función de barrera de su mucosa intestinal, trastornos congénitos graves de la inmunidad, lesiones valvulares cardíacas o en estado de shock. Los pacientes con VIH y/o SIDA se benefician con el consumo de estos agentes. No se ha demostrado que el consumo de probióticos esté asociado causalmente con la obesidad.

La obesidad está asociada con una inflamación de bajo grado que contribuye al desarrollo de la insulino-resistencia y de la diabetes. El objetivo de este estudio fue evaluar las concentraciones plasmáticas de ácidos grasos saturados (AGS), monoinsaturados (AGMI) y poliinsaturados (AGPI) en sujetos obesos asintomáticos y determinar el ratio ácido araquidónico/ácido eicosapentanoico [ARA/EPA] como un posible marcador de inflamación, con su eventual asociación con los niveles de proteína C reactiva ultrasensible (PCRus). Se reclutaron 14 sujetos obesos (34,4 ± 11.1 años; índice de masa corporal: 36,0 ± 4,5 kg/m2) y 12 normopeso (30,6 ± 7.8 años; índice de masa corporal: 23,6 ± 2,4 kg/m2); las concentraciones plasmáticas de ácidos grasos fueron determinados por cromatografía de gases. Los niveles de PCRus fueron más elevadas en los sujetos obesos (p=0,01) y correlacionaron con el contenido de grasa corporal. Los porcentajes relativos de AGS, AGMI, AGPI no se vieron afectados en los sujetos obesos, pero sus concentraciones plasmáticas se incrementaron en comparación con el grupo control. Sin embargo, no se observaron diferencias en las concentraciones de PUFAs de cadena larga (DHA, EPA y ARA) ni en el ratio ARA/EPA en los sujetos obesos. Estas observaciones no apoyan el uso del ratio ARA/EPA como un marcador de inflamación de bajo grado evaluada por PCRus en este grupo de sujetos obesos asintomáticos.

Obesity is associated with a low grade inflammation which contributes to the development of insulin resistance and diabetes. The aim of this study was to assess the total saturated (SFAs), monounsaturated (MUFAs) and polyunsaturated fatty acids (PUFAs) in plasma from asymptomatic obese subjects and to determine the arachidonic/eicosapentanoic acid ratio [ARA/EPA] as a marker of inflammation, and its eventual association with ultrasensitive CRP. Fourteen obese (34.4 ± 11.1y.; BMI: 36.0 ± 4,5 kg/m2) and 12 normal-weight (30.6 ± 7.8y.; BMI: 23,6± 2,4 kg/m2) subjects were recruited and their plasma fatty acids were determined by gas chromatography. usCRP was higher in the obese subjects (p=0,01) and correlates with their body fat content. The percentages of SFAs, MUFAs, PUFAs were not affected in the obese subjects but their concentrations were increased, compared with the control group. However, no differences in the long chain PUFAs (DHA and EPA) concentrations or in the plasmatic ARA/EPA ratio were observed in these subjects. These observations do not support a relation between the ARA/EPA ratio and the presence of low grade inflammation evaluated by plasma usCRP in this group of asymptomatic obese subjects.

Se analizó la biodiversidad de especies de Lactobacillus en muestras de calostro de 116 madres chilenas mediante PCR y secuenciación del rDNA 16S. Se aislaron lactobacilos en 55,3% de las muestras, con concentraciones de 3,33 ± 0,55 (log UFC / ml). Las especies predominantes fueron L. plantarum (64%), L. fermentum (16%) y L. pentosus (9%). 28% de las cepas aisladas fueron resistentes a pH gástrico y a las sales biliares, lo que sugiere que podrían ser utilizados como probióticos.

The biodiversity of Lactobacillus spp. in colostrum samples from 116 Chilean mothers was analyzed by PCR and 16S rDNA sequencing. Lactobacilli were isolated in 55.3% of the samples, with concentrations of 3.33 ± 0.55 (log CFU/ml). The predominant species were L. plantarum (64%), L. fermentum (16%) and L. pentosus (9%). 28% of the isolated strains were resistant to gastric pH and bile salts, suggesting that they could be used as probiotics.

The effect of the consumption of a yogurt with 2.36 g inulin and 1.77g polydextrose was evaluated in 33 healthy and 37 constipated adults, compared with the same product without inulin. The study includes two 5-week periods, one with the experimental product and the other with the control product, separated by a three week wash-out. The subjects had to ingest 1 yougurt/day during the first week of each period, 2/day during the third week and 3/day during the fifth week; simultaneously they had to register daily the intensity of the digestive symptoms as well as the frequency and consistency of their stools. The results showed that in healthy subjects, the intake of 2 yogurts with inulin or more per day significantly increased the digestive symptoms (p=0.03), due to a greater emission of rectal gas (p=0.000). Similar findings were observed in the constipated subjects consuming 3 yogurts daily (p=0.0085 y p=0.0048, respectively); stool frequency and consistency were significantly improved in these subjects (p=0.0039 and p=0.014, respectively). These results suggest that the consumption of 2 yogurts with inulin by day help to fight constipation in subjects with this complain while the intake of this same amount may increase discomfort in healthy subjects

En 33 adultos sanos y 37 constipados se evaluó el efecto del consumo de un yogur que contenía 2.36 g de inulina y 1.77 g de polidextrosa, en comparación con un yogur control sin inulina. El estudio incluyó dos períodos de 5 semanas separados por tres semanas de reposo: uno con el producto experimental y otro con el control. Los sujetos consumieron 1 yogur al día la primera semana de cada período, 2 al día en la tercera y 3 al día en la quinta, y anotaron diariamente la intensidad de los síntomas digestivos así como el número de deposiciones emitidas y su consistencia. Los resultados muestran que a partir de un consumo diario de 2 yogures con inulina existe un aumento significativo de la sintomatología digestiva en los sujetos sanos (p=0.03), debido principalmente a la mayor emisión de gases réctales (p=0.000). Observaciones similares se realizaron en los sujetos constipados con el consumo de 3 productos diarios (p=0.0085 y p=0.0048, respectivamente); sin embargo en aquellos se observó además un mejoramiento significativo tanto en la frecuencia de las deposiciones (p= 0.0039) como en su consistencia (p= 0.014). Este estudio sugiere que el consumo del producto con inulina contribuye a aliviar las molestias de los individuos constipados pero que en los sujetos sanos un consumo de dos yogur al día aumenta los síntomas desagradables

Background: Celiac patients are at high risk of developing insulin-dependent diabetes mellitus, a condition that has a long pre-diabetic period. During this lapse, anti-islet cell antibodies serve as markers for future disease. This may be related with the duration of the exposure to gluten. Aim: To test the hypothesis that long term adherence to a gluten free diet decreases the frequency of risk markers for insulin dependent diabetes mellitus during adolescence and early adulthood. Patients and methods: 158 celiac patients were classified as: G1, (n=30 patients) studied at the time of diagnosis; G2 (n=97 patients) exposed to gluten as a result of non compliance with the gluten free diet and, G3 (n=31 patients) who had maintained a long term, strict gluten free diet. Isotype IgG anti-islet cell antibodies were detected by indirect immunofluorescence using monkey pancreas; results were reported in Juvenile Diabetes Foundation (JDF) units. Results: Celiac patients exposed to a gluten containing diet had a significantly higher prevalence of anti-islet cell antibodies than those who had been exposed only briefly (p <0.017). In addition, a significantly higher prevalence of anti-islet cell antibodies was observed in those patients whose exposure to gluten was longer than 5 years than in those whose exposure was shorter (p <0.02). Conclusions: Celiac patients long exposed to gluten have a significantly higher prevalence of anti-islet cell antibodies than those exposed for a short period. This fact supports the hypothesis that the development of these antibodies is associated with the length of the exposure to gluten (Rev Méd Chile 2004; 132: 979-84)

Background: Endomysium antibodies (EMA) do not detect minor dietary transgressions in patients with celiac disease. Aim: To compare the sensitivity and specificity of tissue transglutaminase antibodies (tTGA) and endomysium antibodies (EMA) in biopsy proven celiac patients at the time of diagnosis and during gluten free diet (GFD). Patients and methods: One hundred fifty three subjects were studied: a) 30 healthy controls; b) 9 cases with cow's milk allergy; c) 24 celiac patients at time of diagnosis; d) 25 celiac patients adhering to the GFD; e) 65 celiac patients with poor/no adhesion to GFD. EMA and tTGA IgA were measured by immunofluorescence and ELISA, respectively. Results: Sensitivity and specificity were 100% and 97.4% for tTGA, respectively. All patients with cow's milk allergy were EMA (-) and 8 of 9 (88.9%) were tTGA (-). In celiac patients not adhering to the GFD, EMA and tTGA positivity were similar (80% and 81,5%, respectively); 95,4% of the subjects tested positive for at least one of them. All patients adhering to GFD were EMA (-) but tTGA were (+) in 28% of them. Conclusions: EMA and tTGA have similar sensitivity and specificity at the time of diagnosis of celiac disease. Positive tTGA in 28% of patients that adhered strictly to the GFD and whose EMA were negative suggest that tTGA may be helpful in detecting minor dietary transgressions and should be further evaluated (Rev Méd Chile 2003; 131: 25-29)

The differentiation, architecture and function of the mucosa of the digestive tract is the result of close interactions between the epithelial cells and their underlying connective tissue. This interaction not only plays a role in the normal morphological organization of the intestinal mucosa but also in the organization and maturation of the enterocytes, the development of some of their enzymatic activities, the transport of nutriens and the restitution of the epithelium following denudation of the surface of villi due to loss of enterocytes. It is thought that disturbances of the cells of the connective tissue, especially of the myofibroblasts as well as of some of the above mentioned mechanisms, participate in the pathogenesis of some gastrointestinal diseases, celiac disease among them. This review summarizes some of the knowledge in this area (Rev Méd Chile 2001; 129: 1333-42

Um modelo preditivo previamente calculado para o risco de saúde selecionou crianças que sofriam de 4 a 5 vezes mais de doenças do que seus pares não selecionados. Resultados preliminares sugeriram que esse risco referia-se a sintomas neuróticos maternos. Para avaliar esta hipótese, 52 mães, cuja criança tinha um escore preditivo positivo (grupo 1) e 52 nas quais este escore era negativo (grupo 2), foram avaliados por meio do Questionário de Saúde Geral de Goldberg (GHQ-30). Um total de 41,9% e 20,5% das mães do grupo 1 e 2, respectivamente, tiveram escores acima de 11 pontos no GHQ-30, o qual ficou estabelecido como o ponto de corte. Conclui-se que entre famílias pobres da cidade de Santiago, mães de crianças com alto risco de diarréia persistente tiveram freqüência aumentada de sistemas neuróticos deficitários. Novos programas visando esse tipo de crianças deveriam incluir apoio psicológico para suas mães.

A previously calculated predictive model for health risk selects infants who suffer 4-5 times more morbidity than their unselected peers. Preliminary results suggested that this risk is related to maternal neurotic symptomatology. To evaluate this hypothesis, 52 consecutive mothers whose infants had a positive predictive score (Group 1) and 52 in whom this was negative (Group 2) were evaluated by means of Goldberg's General Health Questionnaire (GHQ - 30). A total of 41.9% and 20.5% of the mothers in Groups 1 and 2, respectively, scored above 11 points in GHQ-30, established as the cut off point. It is concluded that among poor urban families in Santiago mothers of infants with high risk of persistent diarrhoea have increased frequency of detectable neurotic symptoms. New programs aimed at this type of infant should include psychological support for their mothers.