Mammary amylase: a possible alternate pathway of carbohydrate digestion in infancy

Alpha-Amylase Inhibits Cell Proliferation and Glucose Uptake in Human Neuroblastoma Cell Lines

The present article describes a study of the effects of alpha-amylase (α-amylase) on the human neuroblastoma (NB) cell lines SH-SY5Y, IMR-32, and LA-N-1. NB is the most common malignancy diagnosed in infants younger than 12 months. Some clinical observations revealed an inverse association between the risk of NB development and breastfeeding. α-Amylase which is present in breast milk was shown to have anticancer properties already in the beginning of the 20th century. Data presented here show that pancreatic α-amylase inhibits cell proliferation and has a direct impact on glucose uptake in the human NB cell lines. Our results point out the importance of further research which could elucidate the α-amylase mode of action and justify the presence of this enzyme in breast milk as a possible inhibitor of NB development. α-Amylase can be thus recognized as a potential safe and natural mild/host anticancer agent minimizing chemotherapy-related toxicity in the treatment of NB.

The Functional Power of the Human Milk Proteome

Human milk is the most complete and ideal form of nutrition for the developing infant. The composition of human milk consistently changes throughout lactation to meet the changing functional needs of the infant. The human milk proteome is an essential milk component consisting of proteins, including enzymes/proteases, glycoproteins, and endogenous peptides. These compounds may contribute to the healthy development in a synergistic way by affecting growth, maturation of the immune system, from innate to adaptive immunity, and the gut. A comprehensive overview of the human milk proteome, covering all of its components, is lacking, even though numerous analyses of human milk proteins have been reported. Such data could substantially aid in our understanding of the functionality of each constituent of the proteome. This review will highlight each of the aforementioned components of human milk and emphasize the functionality of the proteome throughout lactation, including nutrient delivery and enhanced bioavailability of nutrients for growth, cognitive development, immune defense, and gut maturation.

The Function and Alteration of Immunological Properties in Human Milk of Obese Mothers

Maternal obesity is associated with metabolic changes in mothers and higher risk of obesity in the offspring. Obesity in breastfeeding mothers appears to influence human milk production as well as the quality of human milk. Maternal obesity is associated with alteration of immunological factors concentrations in the human milk, such as C-reactive protein (CRP), leptin, IL-6, insulin, TNF-Alpha, ghrelin, adiponectin, and obestatin. Human milk is considered a first choice for infant nutrition due to the complete profile of macro nutrients, micro nutrients, and immunological properties. It is essential to understand how maternal obesity influences immunological properties of human milk because alterations could impact the nutrition status and health of the infant. This review summarizes the literature regarding the impact of maternal obesity on the concentration of particular immunological properties in the human milk.

Starch Malabsorption in Infants

Based on the developmental physiology of pancreatic amylase production, starch digestion in young infants was anticipated to be compromised whenever compared with that in older infants and toddlers. This appears to be the case, but with great variability among infants to digest starch. Evidence points to the importance of maltase-glucoamylase in young infants and its effect on starch digestion. These observations have critical importance for recommendations regarding the feeding of starch-containing foods to young infants.

Milk glucosidase activity enables suckled pup starch digestion

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Starch requires six enzymes for digestion to free glucose: two amylases (salivary and pancreatic) and four mucosal maltase activities; sucrase-isomaltase and maltase-glucoamylase. All are deficient in suckling rodents.

Objective

The objective of this study is to test ¹³C-starch digestion before weaning by measuring enrichment of blood ¹³C-glucose in maltase-glucoamylase-null and wild-type mice.

Methods

Maltase-glucoamylase gene was ablated at the N-terminal. Dams were fed low ¹³C-diet and litters kept on low ¹³C-diet. Pups were weaned at 21 days. Digestion was tested at 13 and 25 days by intragastric feeding of amylase predigested ¹³C-α-limit dextrins. Blood ¹³C-glucose enrichment was measured by gas chromatography combustion isotope ratio mass spectrometry (GCRMS) using penta-acetate derivatives.

Results

Four hours after feeding, blood ¹³C-glucose was enriched by 26 × 10³ in null and 18 × 10³ in wild-type mice at 13 days and 0.3 × 10³ and 0.2 × 103 at 25 days (vs. fasting p = 0.045 and p = 0.045). By jejunal enzyme assay, immunohistochemistry, or Western blots, there was no maltase activity or brush border staining with maltase-glucoamylase antibodies at 13 days, but these were fully developed in the wild-type mice by 25 days. In 13-day null mice, luminal contents were stained by maltase-glucoamylase antibodies. Lactating the mammary gland revealed maltase-glucoamylase antibody staining of alveolar cells. Reverse transcription/polymerase chain reaction (RT/PCR) of lactating glands revealed a secreted form of maltase-glucoamylase.

Conclusions

(1) ¹³C-α-limit dextrins were rapidly digested to ¹³C-glucose in 13-day mice independent of maltase-glucoamylase genotype or mucosal maltase activity. (2) This experiment demonstrates that a soluble maltase activity is secreted in mouse mother’s milk which enables suckling pup starch digestion well before brush border enzyme development. (3) This experiment with ¹³C-α-limit dextrins needs to be repeated in human breast fed infants.

Systematic review of the impact of feed protein type and degree of hydrolysis on gastric emptying in children

Background

The choice of infant formula is thought to play an important role on gastric emptying (GE) in a variety of gastrointestinal disorders. It is known that many ingredients impact on GE, including the type of protein and level of hydrolysis. In clinical practice, feeds are often recommended due to putative improved GE related to the type of protein and level of hydrolysis, however whether this is scientifically justified still needs to be established. A systematic review comparing the impact of protein type and hydrolysis on GE in children was therefore performed.

Methods

The Patient, Intervention, Comparison and Outcome system was used. A structured literature search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, searching PubMed, Cochrane databases and Google Scholar from 1990 to 2014. We only included articles published in full text English language using specific search terms, including both scintigraphy and C13-octanoic acid breath test.

Results

We identified 126 publications of which 20 were eligible for inclusion but only 8 were included. Studies reviewed GE in both healthy children as well as those with neurodevelopmental delay and reflux. Two studies investigating GE of breast milk versus formula indicated a faster GE for breast milk. Four studies found that feeds containing whole whey in varying amounts emptied faster than predominant whole casein feeds and one study found no difference in GE. Five studies investigated a mix of whole versus hydrolysed protein and found conflicting results related to study population and hydrolysis.

Conclusions

Breast milk has a faster GE than formula milk. Although there seems to be a trend towards whey feeds emptying faster, different methodologies, feed compositions and patient groups makes it difficult to draw firm conclusions. Future studies should be performed with comparable feeds in populations where increased GE may be of clinical benefit.

Lactase persistence and augmented salivary alpha-amylase gene copy numbers might have been selected by the combined toxic effects of gluten and (food born) pathogens

Various positively selected adaptations to new nutrients have been identified. Lactase persistence is among the best known, conferring the ability for drinking milk at post weaning age. An augmented number of amylase gene (AMY1) copies, giving rise to higher salivary amylase activity, has been implicated in the consumption of starch-rich foods. Higher AMY1 copy numbers have been demonstrated in populations with recent histories of starchy-rich diets. It is however questionable whether the resulting polymorphisms have exerted positive selection only by providing easily available sources of macro and micronutrients. Humans have explored new environments more than any other animal. Novel environments challenge the host, but especially its immune system with new climatic conditions, food and especially pathogens. With the advent of the agricultural revolution and the concurrent domestication of cattle came new pathogens. We contend that specific new food ingredients (e.g., gluten) and novel pathogens drove selection for lactase persistence and higher AMY gene copy numbers. Both adaptations provide ample glucose for activating the sodium glucose-dependent co-transporter 1 (SGLT1), which is the principal glucose, sodium and water transporter in the gastro-intestinal tract. Their rapid uptake confers protection against potentially lethal dehydration, hyponatremia and ultimately multiple organ failure. Oral rehydration therapy aims at SGLT1 activity and is the current treatment of choice for chronic diarrhoea and vomiting. We hypothesize that lifelong lactase activity and rapid starch digestion should be looked at as the evolutionary covalent of oral rehydration therapy.

Effects of 50 Hz magnetic field exposure on the stress marker α-amylase in the rat mammary gland

PURPOSE

Concerns about adverse health effects of environmental exposure to 50/60 Hz magnetic fields (MF) have initiated numerous studies on laboratory animals with varying outcomes. Previously, we reported that rat strains responded differently to MF regarding mammary cell proliferation and tumor development indicating that (epi)genetic factors might influence MF effects in the breast tissue, yet without any identified mechanism. In the present study, α-amylase, recently introduced as a stress marker in humans, was investigated in the mammary gland of Fischer 344 (F344) and Lewis rats, two strains with distinct stress sensitivity.

MATERIALS AND METHODS

F344 rats were sham- and MF-exposed (50 Hz, 100 μT) for different time periods, Lewis rats for two weeks. For comparison, diethylstilbestrol was administered at single or repeated doses.

RESULTS

α-Amylase activity was significantly enhanced in the F344 mammary glands after 2 and 4 weeks of MF, whereas no reproducible effects were observed in Lewis rats. Diethylstilbestrol increased the α-amylase after repeated dosing.

CONCLUSIONS

Although α-amylase represents a difficult parameter in animal studies because of its stress sensitivity, it should be considered for investigations in humans and cell cultures as a biomarker for MF susceptibility and a target to examine possible MF mechanisms since α-amylase affects cell growth.

Gene expression in the mammary gland tissue of female Fischer 344 and Lewis rats after magnetic field exposure (50 Hz, 100 μT) for 2 weeks

PURPOSE

The issue of whether exposure to environmental power-frequency magnetic fields (MF) has impact on breast cancer development still remains equivocal. Previously, we observed rat strain differences in the MF response of breast tissue, so that the genetic background plays a role in MF effects. The present experiment aimed to elucidate candidate genes involved in MF effects by comparison of MF-susceptible Fischer 344 (F344) rats and MF-insensitive Lewis rats.

MATERIALS AND METHODS

Female F344 and Lewis rats were exposed to MF (50 Hz, 100 μT) for two weeks, and a whole genome microarray analysis in the mammary gland tissue was performed.

RESULTS

A remarkably decreased α-amylase gene expression, decreases in carbonic anhydrase 6 and lactoperoxidase, both relevant for pH regulation, and an increased gene expression of cystatin E/M, a tumor suppressor, were observed in MF-exposed F344, but not in Lewis rats.

CONCLUSION

The MF-exposed F344 breast tissue showed alterations in gene expression, which were absent in Lewis and may therefore be involved in the MF-susceptibility of F344. Notably α-amylase might serve as a promising target to study MF effects, because first experiments indicate that MF exposure alters the functionality of this enzyme in breast tissue.

Salivary α-amylase exhibits antiproliferative effects in primary cell cultures of rat mammary epithelial cells and human breast cancer cells

Background

Breast cancer is one of the most diagnosed cancers in females, frequently with fatal outcome, so that new strategies for modulating cell proliferation in the mammary tissue are urgently needed. There is some, as yet inconclusive evidence that α-amylase may constitute a novel candidate for affecting cellular growth.

Methods

The present investigation aimed to examine if salivary α-amylase, an enzyme well known for the metabolism of starch and recently introduced as a stress marker, is able to exert antiproliferative effects on the growth of mammary gland epithelial cells.

For this purpose, primary epithelial cultures of breast tissue from two different inbred rat strains, Fischer 344 (F344) and Lewis, as well as breast tumor cells of human origin were used. Treatment with human salivary α-amylase was performed once daily for 2 days followed by cell counting (trypan blue assay) to determine alterations in cell numbers. Cell senescence after α-amylase treatment was assessed by β-galactosidase assay. Endogenous α-amylase was detected in cells from F344 and Lewis by immunofluorescence.

Results

Salivary α-amylase treatment in vitro significantly decreased the proliferation of primary cells from F344 and Lewis rats in a concentration-dependent manner. Noticeably, the sensitivity towards α-amylase was significantly higher in Lewis cells with stronger impact on cell growth after 5 and 50 U/ml compared to F344 cells. An antiproliferative effect of α-amylase was also determined in mammary tumor cells of human origin, but this effect varied depending on the donor, age, and type of the cells.

Conclusions

The results presented here indicate for the first time that salivary α-amylase affects cell growth in rat mammary epithelial cells and in breast tumor cells of human origin. Thus, α-amylase may be considered a novel, promising target for balancing cellular growth, which may provide an interesting tool for tumor prophylaxis and treatment.

Activities of gastric, pancreatic, and intestinal brush-border membrane enzymes during postnatal development of dogs

OBJECTIVE

To measure activities of digestive enzymes during postnatal development in dogs.

SAMPLE POPULATION

Gastrointestinal tract tissues obtained from 110 Beagles ranging from neonatal to adult dogs.

PROCEDURE

Pepsin and lipase activities were measured in gastric contents, and amylase, lipase, trypsin, and chymotrypsin activities were measured in small intestinal contents and pancreatic tissue. Activities of lactase, sucrase, 4 peptidases, and enteropeptidase were assayed in samples of mucosa obtained from 3 regions of the small intestine.

RESULTS

Gastric pH was low at all ages. Pepsin was not detected until day 21, and activity increased between day 63 and adulthood. Activities of amylase and lipase in contents of the small intestine and pancreatic tissue were lower during suckling than after weaning. Activities of trypsin and chymotrypsin did not vary among ages for luminal contents, whereas activities associated with pancreatic tissue decreased between birth and adulthood for trypsin but increased for chymotrypsin. Lactase and gamma-glutamyltranspeptidase activities were highest at birth, whereas the activities of sucrase and the 4 peptidases increased after birth. Enteropeptidase was detected only in the proximal region of the small intestine at all ages.

CONCLUSIONS AND CLINICAL RELEVANCE

Secretions in the gastrointestinal tract proximal to the duodenum, enzymes in milk, and other digestive mechanisms compensate for low luminal activities of pancreatic enzymes during the perinatal period. Postnatal changes in digestive secretions influence nutrient availability, concentrations of signaling molecules, and activity of antimicrobial compounds that inhibit pathogens. Matching sources of nutrients to digestive abilities will improve the health of dogs during development.

Routine handling of milk fed to preterm infants can significantly increase osmolality

BACKGROUND

The purpose of these studies was to evaluate the changes in osmolality which occur in human breast milk or formula after two modifications; these changes are sometimes used in preparing these milks for consumption by premature infants, namely, the addition of fortifiers and the addition of exogenous lactase enzyme.

METHODS

The osmolality of expressed, previously frozen human breast milk, breast milk fortified with commercial fortifiers, liquid formulas, powdered formulas, or glucose polymers was measured. Osmolality was measured before and after warming (15 minutes at 37 degrees C) or after refrigeration at 4 degrees C for 12 hours with subsequent warming. In a second group of experiments, the osmolality of expressed breast milk and three lactose-containing formulas was measured before and after incubation with lactase (Lactaid ) at 4 degrees C for 2, 6, and 24 hours.

RESULTS

Warming of breast milk mixed with some of the additives was associated with a significant increase in osmolality. The additives which increased osmolality included liquid glucose polymers, two commercially available powdered human milk fortifiers, and three formulas which contain glucose polymers (a protein hydrolysate infant formula powder, powdered lactose free formula, and a powdered preterm formula). Maximum increase in osmolality of breast milk occurred with the addition of 20 ml/100ml liquid glucose polymers (Polycose, Ross Laboratories) which resulted in a 21% increase in osmolality after refrigeration and warming. The addition of liquid glucose polymers and of powdered preterm formulas containing glucose polymers (Enfacare, Mead Johnson, 9.5 g/100ml and Nutramigen, Mead Johnson, 6 g/100ml) resulted in a final osmolality of over 425 mOsmol/L. The addition of lactase and subsequent incubation under refrigeration resulted in significant increases in osmolality that ranged from 25 to 66% in fortified breast milks and lactose-containing formulas. Incubation of these milks at 37 degrees for 15 minutes produced about 50% greater increase in osmolality than observed after 2 hours of incubation under refrigeration.

CONCLUSIONS

Routine warming of breast milk with glucose polymer-containing additives, or the addition of lactase enzyme to lactose-containing feedings, can increase osmolality to levels that exceed current guidelines for premature infant feedings.

Human milk oligosaccharides are resistant to enzymatic hydrolysis in the upper gastrointestinal tract

BACKGROUND

Human milk oligosaccharides (HMOs) show a complexity and variety not found in milk of any other species. Although progress has been made in the past 3 decades with regard to identification and structural characterization of HMOs, not much is known about the physiologic functions of HMOs.

OBJECTIVE

As a prerequisite for biological activity in infant metabolism, HMOs have to resist enzymatic hydrolysis in the gastrointestinal tract. To assess the extent to which selected HMOs are hydrolyzed, we carried out in vitro digestion studies using enzyme preparations of human and porcine pancreas and intestinal brush border membranes (BBMs).

DESIGN

Fractions of HMOs, including structurally defined isolated oligosaccharides, were digested for up to 20 h with human pancreatic juice and BBMs prepared from human or porcine intestinal tissue samples. HMOs were incubated by using a porcine pancreatic homogenate and BBMs as enzyme sources. HMOs and digestion products were identified by mass spectrometry and anion-exchange chromatography. Additionally, free D-glucose, L-fucose, and N-acetylneuraminic acid were determined enzymatically.

RESULTS

Whereas maltodextrin (control) was rapidly and completely hydrolyzed, neutral and acidic HMOs showed a profound resistance against pancreatic juice and BBM hydrolases. However, cleavage of most of the HMOs was achieved by using a pancreatic homogenate containing intracellular, including lysosomal, enzymes in addition to secreted enzymes.

CONCLUSIONS

The results of this study strongly suggest that HMOs are not hydrolyzed by enzymes in the upper small intestine. Although intact HMOs may be absorbed, we postulate that a majority of HMOs reach the large intestine, where they serve as substrates for bacterial metabolism. Therefore, HMOs might be considered the soluble fiber fraction of human milk.

Gastric lipase and pepsin activities in the developing ferret: nonparallel development of the two gastric digestive enzymes

BACKGROUND

Gastric lipase has an important compensatory function in neonatal fat digestion. The activity level of pepsin and its role in protein digestion is less well understood. We have, therefore, studied the ontogeny of lipase and pepsin in the ferret, a species with a neonatal fat digestion pattern similar to that of humans.

METHODS

Gastric lipase and pepsin activities were quantified from the late fetal period throughout lactation, and were compared with those of the adult.

RESULTS

The data show earlier ontogeny and much more rapid rise of lipase activity than of pepsin. Lipase activity was present during the last week of fetal development, whereas pepsin was detected only postnatally. Lipase activity was 72.8% +/- 14.2% and 153% +/- 9.95% and pepsin activity was 11.6% +/- 1.3% and 30.1% +/- 1.3% of the adult level at 2 and 4 wk of age, respectively.

CONCLUSIONS

We conclude that lipase activity develops early and exceeds adult activity during the suckling period, when fat intake is very high. The low pepsin activity and high postprandial pH probably limit gastric proteolysis, thereby contributing to the structural and functional stability of milk proteins, many with protective or bioactive function in the gastrointestinal tract of the newborn.

Is rice based oral rehydration therapy effective in young infants?

Rice based oral rehydration therapy (ORT) solutions have been shown to be superior to glucose oral rehydration salts (World Health Organisation (WHO) ORS) in reducing stool volume and duration of diarrhoea in children and adults. Rice based ORT has been used only sparingly in young infants, however, because of theoretical concerns about digestibility. A randomised controlled trial of rice based ORT (50 g rice and electrolytes identical to WHO ORS) and WHO ORS was carried out in 52 male infants less than 6 months old with moderately severe acute diarrhoea to evaluate efficacy and digestibility. Nineteen (70%) of 27 children who received rice based ORT and 18 (72%) of 25 children who received WHO ORS were treated successfully. The mean (SD) diarrhoeal stool output for the first 24 hours of treatment was significantly lower in the infants receiving the rice based ORT than in those receiving WHO ORS (101.0 (60.5) v 137.1 (74.6) g/kg). The stool output was also significantly less in the rice based ORT group in the second 24 hours. Infants in the rice based ORT group drank significantly less rehydration solution than infants in the WHO ORS group (mean (SD) 165.4 (77.4) v 217.9 (86.1) during the first 24 hours of treatment. There was no difference in the duration of diarrhoea between the groups. The volume of breast and formula feeding was similar in the two groups. No difference was seen in the frequency of finding reducing substances or acid pH in the stools of either group of children. The results suggest that rice based ORT is as effective as WHO ORS in infants with moderately severe diarrhoea and that rice based ORT is as well tolerated as WHO ORS in infants.

Breast feeding and the older infant

The possible benefits and disadvantages to the older infant of breast-feeding being continued after the introduction of solid foods are reviewed. The limited evidence from industrialised countries suggests that prolonged partial breast-feeding has little influence on child health and growth. In contrast, in poor areas of the developing world, the continuation of breast-feeding for 1-2 years after the introduction of other foods appears to have several major benefits. These include the supply of nutrients, the delivery of protective, digestive and trophic agents, and extending the period of infertility in the mother. Partial breast-feeding after 6 months is associated with reduced severity of infectious diseases particularly in severely malnourished individuals. There is no evidence that partial breast-feeding plays a causal role in poor growth performance. In poor areas of the developing world, breast-feeding, together with the provision of adequate amounts of other foods, should be encouraged for the first two years of life.

Hydrolysis and absorption of glucose polymers from rice compared with corn in chronic diarrhea of infancy

Because rice remains the most available carbohydrate in developing countries, where chronic diarrhea is most prevalent, we compared the in vitro hydrolysis and clinical tolerance of rice glucose polymer with those of corn glucose polymer. Rice glucose polymer hydrolysis to D-glucose and short-chain polymers (polymers with two to four glucose units and those with five or more units) was similar to that for corn glucose polymers during incubation with saliva or duodenal aspirates. However, rice glucose polymers yielded more short-chain products than corn glucose polymers during incubation with pooled mucosal homogenates (p less than 0.01). In vivo tolerance testing of 16 infants with chronic diarrhea confirmed that rice glucose polymers were well tolerated and, compared with corn glucose polymers, achieved a higher maximal increase of serum glucose concentration (36.6 +/- 7.3 vs 27.6 +/- 10.3 mg/dl; p less than 0.02), a shorter time to peak serum glucose concentration (34.0 +/- 10.2 vs 52.5 +/- 25.7 minutes; p less than 0.02), and a greater area under the serum glucose response curve at 30 minutes (538 +/- 131 vs 1035 +/- 501 cm; p less than 0.02). We conclude that rice glucose polymers are rapidly hydrolyzed in vitro and in vivo and are more rapidly absorbed than are corn glucose polymers in children with chronic diarrhea.

Disorders of carbohydrate digestion and absorption

The carbohydrate malabsorptive syndromes are frequently seen by pediatricians. The congenital deficiency states are quite rare, but adult type hypolactasia and lactose intolerance following rotavirus infection are recognized with increasing frequency by primary care physicians. Therapy for these disorders involves identification of the offending carbohydrate, removal of the carbohydrate from the diet, and exclusion of other entities that may result in carbohydrate malabsorption but not respond to its removal from the diet. Prognosis for both the primary and secondary carbohydrate malabsorption syndromes is excellent. Compliance with diets for those pediatric patients who will require lifelong therapy remains problematic.

Biochemistry of human alpha amylase isoenzymes

The purpose of this article is to review recent literature on the isoenzymes of alpha amylase. Although some studies are cited from the literature of fields other than clinical biochemistry, the aim is to bring together findings that may be of interest to clinical laboratory physicians and scientists. It is hoped that this will be useful in suggesting further studies of amylase. To this end, the review is more selective than exhaustive. The review will discuss the history and chemistry alpha amylases, the measurement of amylase and amylase isoenzymes, posttranslational modifications of human amylases, and the genetics of human pancreatic and salivary amylases. Finally, we will discuss other tissue sources of amylase with emphasis on "genital" amylases and their relationship to the amylase found in serous ovarian tumors.

Corn syrup sugars: in vitro and in vivo digestibility and clinical tolerance in acute diarrhea of infancy

We evaluated the in vitro and in vivo digestibility and clinical tolerance of three corn syrup sugars (DE10, 15, 24) and one infant formula containing corn syrup sugar as the sole carbohydrate source (DE24). In vitro studies were conducted using human duodenal fluid and jejunal mucosa with normal enzyme activities. In vivo studies included intragastric perfusion studies and tolerance tests using the corn syrup sugars and a clinical formula trial in 32 infants with acute diarrhea. Results of the in vitro studies showed that each of the corn syrup sugars was well hydrolyzed by duodenal fluid and by mixtures of duodenal fluids and mucosal homogenates. Similarly, in vivo studies revealed significant hydrolysis in the proximal intestine, as measured during the perfusion studies, and adequate absorption, as indicated by a rise in serum glucose concentration during tolerance tests. Only patients who had a marginal serum glucose rise after a glucose meal had a blunted rise after a corn syrup feeding. More than 85% of the infants beginning the clinical trial tolerated the formula well and gained weight at or above the expected rate for age during the study interval. These data indicate that, except with severe mucosal injury and secondary monosaccharide intolerance, glucose polymers of the dextrose equivalents tested are suitable carbohydrate sources for infants recovering from acute diarrhea.