Linking fat intake, the intestinal microbiome, and necrotizing enterocolitis in premature infants

Comparison of human breast milk vs commercial formula-induced early trophic enteral nutrition during postoperative prolonged starvation in an animal model

The present study aimed to characterize the changes in macromolecular composition and structure in ileal tissue induced by postoperative prolonged starvation (PS), human breast milk feeding (HM) and commercial formula feeding (CF) for 48 and 72 h (h). Forty-two Wistar albino rats underwent an ileal transection and primary anastomosis and were then divided into six subgroups. Two groups of seven rats were food-deprived for 48 and 72 h with free access to water only in metabolic cages (48 h PS, 72 h PS). Then, two groups of seven rats received early enteral trophic nutrition (EEN) either using HM, and CF at 48 h post-operation (48 h HM, 48 h CF). The other two groups of seven rats received the same trophic enteral nutrition at 72 h post-operation (72 h HM, 72 h CF). An additional seven rats were fed normal rat chow (control), after which the ileal tissues were harvested and freeze-dried overnight. Then sample spectra were recorded by Fourier transform infrared (FTIR) spectroscopy. PS at 48 and 72 h resulted in an increase in the concentration of lipids and a decrease in the concentration of proteins. CF and HM trophic feeding induced a decrease in membrane fluidity and an increase in lipid order. Ileal tissues showed similar compositional and structural changes in lipids and proteins in the PS and CF groups after 48 and 72 h. A marked decrease in nucleic acid concentration was seen in CF at 48 h compared to HM. The human milk feeding groups did not induce any significant alterations and showed compositional and structural data similar to the controls. In conclusion, EEN application seems to be safer when introduced at 48 h rather than 72 h and time of this nutrition is crucial to maintain ileum structure and therefore immunity and well-being. HM-induced trophic nutrition is seen to protect the ileal tissue from significant alterations within lipid and protein compositions, whereas CF caused notable changes. HM is absolutely the best nutritional source for gut health in this animal model.

Human behavior, not race or geography, is the strongest predictor of microbial succession in the gut bacteriome of infants

Colonization of the gastrointestinal tract with microorganisms during infancy represents a critical control point for shaping life-long immune-mediated disease susceptibility. Abnormal colonization or an imbalance of microbes, termed dysbiosis, is implicated in several diseases. Consequently, recent research has aimed at understanding ways to manipulate a dysbiotic microbiome during infancy to resemble a normal, healthy microbiome. However, one of the fundamental issues in microbiome research is characterizing what a "normal" infant microbiome is based on geography, ethnicity and cultural variations. This review provides a comprehensive account of what is currently known about the infant microbiome from a global context. In general, this review shows that the influence of cultural variations in feeding practices, delivery modes and hygiene are the biggest contributors to microbial variability. Despite geography or race, all humans have similar microbial succession during infancy.

The Development of the Human Microbiome: Why Moms Matter

The human body is cohabitated with trillions of commensal bacteria that are essential for our health. However, certain bacteria can also cause diseases in the human host. Before the microbiome can be attributed to disease risk and pathogenesis, normal acquisition and development of the microbiome must be understood. Here, we explore the evidence surrounding in utero microbial exposures and the significant of this exposure in the proper development of the fetal and neonatal microbiome. We further explore the development of the fetal and neonatal microbiome and its relationship to preterm birth, feeding practices, and mode of delivery, and maternal diet.

Inherited nongenetic influences on the gut microbiome and immune system

The gut microbiome and the immune system codevelop around the time of birth, well after genetic information has been passed from the parents to the offspring. Each of these "organ systems" displays plasticity. The immune system can mount highly specific adaptive responses to newly encountered antigens, and the gut microbiota is affected by changes in the environment. Despite this plasticity, there is a growing appreciation that these organ systems, once established, are remarkably stable. In health, the immune system rapidly mounts responses to infections, and once cleared, resolves inflammatory responses to return to homeostasis. However, a skewed immune system, such as seen in allergy, does not easily return to homeostasis. Allergic responses are often seen to multiple antigens. Likewise, a dysbiotic gut microbiota is seen in multiple diseases. Attempts to reset the gut microbiota as a therapy for disease have met with varied success. Therefore, how these codeveloping "organ systems" become established is a central question relevant to our overall health. Recent observations suggest that maternal factors encountered both in utero and after birth can directly or indirectly impact the development of the offspring's gut microbiome and immune system. Here, we discuss how these nongenetic maternal influences can have long-term effects on the progeny's health.

Epigenetic Mechanisms Link Maternal Diets and Gut Microbiome to Obesity in the Offspring

Nutrition is the most important environmental factor that can influence early developmental processes through regulation of epigenetic mechanisms during pregnancy and neonatal periods. Maternal diets or nutritional compositions contribute to the establishment of the epigenetic profiles in the fetus that have a profound impact on individual susceptibility to certain diseases or disorders in the offspring later in life. Obesity is considered a global epidemic that impairs human life quality and also increases risk of development of many human diseases such as diabetes and cardiovascular diseases. Studies have shown that maternal nutrition status is closely associated with obesity in progenies indicating obesity has a developmental origin. Maternal diets may also impact the early establishment of the fetal and neonatal microbiome leading to specific epigenetic signatures that may potentially predispose to the development of late-life obesity. This article will review the association of different maternal dietary statuses including essential nutritional quantity and specific dietary components with gut microbiome in determining epigenetic impacts on offspring susceptibility to obesity.

Standardized slow enteral feeding protocol reduces necrotizing enterocolitis in micropremies

BACKGROUND

Compared to early enteral feeds, delayed introduction and slow enteral feeding advancement to reduce necrotizing enterocolitis (NEC) is not well studied in micropremies (<750g birth weight).

METHODS

Pre-post case control study. Micropremies who followed a standardized slow enteral feeding (SSEF) protocol (September 2009 to March 2015) were compared with a similar group of historical controls (PreSSEF, January 2003 to July 2009). Enteral feeding withheld for first 10-14 days and advanced at <10 ml/kg/day in the SSEF group.

RESULTS

Ninety-two infants in the SSEF group were compared with 129 PreSSEF group. Birth weight and gestational age in SSEF and PreSSEF were similar. Breast milk initiation rate was higher in SSEF (87.0 vs. 72.0%, p = 0.01) compared to PreSSEF, but were similar at full enteral feeds. Compared with PreSSEF, feeding initiation day, full enteral feeding day, parenteral nutrition days, and total central line days were longer in SSEF. There was significant reduction in NEC (1.1 vs. 16.2%, p < 0.01), surgical NEC (0.0 vs. 7.8%, p < 0.01) and NEC/death (7.6 vs. 29.5%, p < 0.01), in SSEF compared to PreSSEF. SSEF, compared to PreSSEF, had more cholestasis (41.8 vs 28.8%, p = 0.04), higher peak serum alkaline phosphatase (638 vs. 534 IU/dL, p < 0.01), but similar rates of late-onset sepsis (39.1 vs 43.4%, p = 0.53). In infants who survived to discharge, SSEF had higher discharge weight, lower extra-uterine growth restriction, and similar length of stay, compared to PreSSEF.

CONCLUSIONS

A SSEF protocol significantly reduces the incidence of NEC and combined NEC/death in micropremies.

Systematic Review of the Effect of Enteral Feeding on Gut Microbiota in Preterm Infants

OBJECTIVE

To examine the effect of feeding type on microbial patterns among preterm infants and to identify feeding factors that promote the colonization of beneficial bacteria.

DATA SOURCES

PubMed, Cochrane Database of Systematic Reviews, Scopus, and the Cummulative Index of Nursing and Allied Health Literature were thoroughly searched for articles published between January 2000 and January 2017, using the keywords gut microbiome, gut microbiota, enteral microbiome, enteral microbiota, premature infant, preterm infant, extremely low birth weight infant, ELBW infant, very low birth weight infant, feeding, breast milk, breastfeeding, formula, prebiotic, probiotic, and long chain polyunsaturated fatty acid.

STUDY SELECTION

Primary studies written in English and focused on the association between enteral feeding and gut microbiome patterns of preterm infants were included in the review.

DATA EXTRACTION

We independently reviewed the selected articles and extracted information using predefined data extraction criteria including study design, study participants, type of feeding, type and frequency of biospecimen (e.g., feces, gastric aspirate) collection, microbiological analysis method, and major results.

DATA SYNTHESIS

In 4 of the 18 studies included in the review, researchers described the effects of milk products (mothers' own milk, donor human milk, and formula). In 5 studies, the effects of prebiotics were assessed, and in 9 studies, the effects of probiotics on the gut microbiome were described. Mothers' own breast milk feeding influenced the compositional structure of preterm infants' gut microbial community and increased diversity of gut microbiota compared with donor human milk and formula feeding. The results of the use of prebiotics and probiotics varied among studies; however, the majority of the researchers reported positive bifidogenic effects on the development of beneficial bacteria.

CONCLUSION

Mothers' own milk is considered the best form of nutrition for preterm infants and the gut microbial community. Variation in fatty acid composition across infant feeding types can affect microbial composition. The evidence for supplementation of prebiotics and probiotics to promote the gut microbial community structure is compelling; however, additional research is needed in this area.

ANGPTL4 promotes bile acid absorption during taurocholic acid supplementation via a mechanism dependent on the gut microbiota

Angiopoietin-like 4 (ANGPTL4) raises plasma triglyceride levels by inhibiting lipoprotein lipase. A set of compounds that are able to reduce plasma triglyceride levels are bile acids (BA). Because BA have been shown to decrease ANGPTL4 secretion by intestinal cells, we hypothesized that BA lower plasma triglycerides (partly) via ANGPTL4. To test that hypothesis, wild-type and Angptl4^-/- mice were fed chow supplemented with taurocholic acid (TCA) for seven days. TCA supplementation effectively lowered plasma triglycerides in wild-type and Angptl4^-/- mice, indicating that ANGPTL4 is not required for plasma triglyceride-lowering by BA. Intriguingly, however, plasma and hepatic BA concentrations were significantly lower in TCA-supplemented Angptl4^-/- mice than in TCA-supplemented wild-type mice. These changes in the Angptl4^-/- mice were accompanied by lower BA levels in ileal scrapings and decreased expression of FXR-target genes in the ileum, including the BA transporter Slc10a2. By contrast, faecal excretion of specifically primary BA was higher in the Angptl4^-/- mice, suggesting that loss of ANGPTL4 impairs intestinal BA absorption. Since the gut microbiota converts primary BA into secondary BA, elevated excretion of primary BA in Angptl4^-/- mice may reflect differences in gut microbial composition and/or functionality. Indeed, colonic microbial composition was markedly different between Angptl4^-/- and wild-type mice. Suppression of the gut bacteria using antibiotics abolished differences in plasma, hepatic, and faecal BA levels between TCA-supplemented Angptl4^-/- and wild-type mice. In conclusion, 1) ANGPTL4 is not involved in the triglyceride-lowering effect of BA; 2) ANGPTL4 promotes BA absorption during TCA supplementation via a mechanism dependent on the gut microbiota.

Mosapride combined with probiotics on gastrointestinal function and growth in premature infants

The aim of this study was to investigate the effects of mosapride combined with probiotics on gastrointestinal function and growth and development in premature infants. A total of 240 premature infants treated at Weifang People's Hospital between June 2012 and May 2015 who matched our criteria were randomly divided into three groups of 80 cases each. Group A received routine treatment, group B received routine treatment combined with live B. subtilis and E. faecium granules with multivitamins (Medilac-Vita), and group C received routine treatment and Saccharomyces boulardii sachets (Bioflor). Mosapride was administered to patients in groups B and C to promote intestinal peristalsis. Gastrin and bilirubin levels, as well as jaundice fade time, were recorded. Growth and development condition (i.e., head circumference and weight), duration and incidence of feeding intolerance (FI), as well as other symptoms were also analyzed. By day 14, gastrin concentrations in groups B and C were significantly higher than those in group A (P<0.05). Serum bilirubin levels in groups B and C showed a progressive decline from day 7 to day 14, and jaundice duration in group A was significantly longer (P<0.05). Furthermore, at 2 weeks, the average weight growth rate and head circumference were significantly greater in groups B and C, weight loss recovery time was shorter, and EUGR incidence was lower (P<0.05). The incidence rate of gastric retention and FI were lower in groups B and C than group A (P<0.05), and neonatal hyperbilirubinemia, parenteral nutrition-associated cholestasis, necrotizing enterocolitis, and neonatal sepsis incidence was significantly lower in groups B and C (P<0.05). Mosapride combined with probiotics can effectively reduce FI incidence in premature infants, shorten enteral feeding time, promote the absorption of required nutrients, and promote the development and recovery of early physiological weight loss in preterm infants.

Distinct Patterns in Human Milk Microbiota and Fatty Acid Profiles Across Specific Geographic Locations

Breast feeding results in long term health benefits in the prevention of communicable and non-communicable diseases at both individual and population levels. Geographical location directly impacts the composition of breast milk including microbiota and lipids. The aim of this study was to investigate the influence of geographical location, i.e., Europe (Spain and Finland), Africa (South Africa), and Asia (China), on breast milk microbiota and lipid composition in samples obtained from healthy mothers after the 1 month of lactation. Altogether, 80 women (20 from each country) participated in the study, with equal number of women who delivered by vaginal or cesarean section from each country. Lipid composition particularly that of polyunsaturated fatty acids differed between the countries, with the highest amount of n-6 PUFA (25.6%) observed in the milk of Chinese women. Milk microbiota composition also differed significantly between the countries (p = 0.002). Among vaginally delivered women, Spanish women had highest amount of Bacteroidetes (mean relative abundance of 3.75) whereas Chinese women had highest amount of Actinobacteria (mean relative abundance 5.7). Women who had had a cesarean section had higher amount of Proteobacteria as observed in the milk of the Spanish and South African women. Interestingly, the Spanish and South African women had significantly higher bacterial genes mapped to lipid, amino acid and carbohydrate metabolism (p < 0.05). Association of the lipid profile with the microbiota revealed that monounsaturated fatty acids (MUFA) were negatively associated with Proteobacteria (r = -0.43, p < 0.05), while Lactobacillus genus was associated with MUFA (r = -0.23, p = 0.04). These findings reveal that the milk microbiota and lipid composition exhibit differences based on geographical locations in addition to the differences observed due to the mode of delivery.

Impact of maternal nutrition in pregnancy and lactation on offspring gut microbial composition and function

Evidence supporting the Developmental Origins of Health and Disease Hypothesis indicates that maternal nutrition in pregnancy has a significant impact on offspring disease risk later in life, likely by modulating developmental processes in utero. Gut microbiota have recently been explored as a potential mediating factor, as dietary components strongly influence microbiota abundance, function and its impact on host physiology. A growing body of evidence has additionally indicated that the intrauterine environment is not sterile as once presumed, indicating that maternal-fetal transmission of microbiota may occur during pregnancy. In this article, we will review the body of literature that supports this emerging hypothesis, as well as highlight the work in relevant animal models demonstrating associations with maternal gestational nutrition and the offspring gut microbiome that may influence offspring physiology and susceptibility to disease.

Early-Life Exposure to Antibiotics, Alterations in the Intestinal Microbiome, and Risk of Metabolic Disease in Children and Adults

The intestinal microbiome is a complex ecosystem of microorganisms that colonize the human gastrointestinal tract. The microbiome evolves rapidly in early life with contributions from diet, genetics and immunomodulatory factors. Changes in composition of the microbiota due to antibiotics may lead to negative long-term effects including obesity and diabetes mellitus, as evidenced by both animal and large human studies. Inappropriate exposures to antibiotics occur frequently in early childhood. Therefore, an evidence-based system of antimicrobial use should be employed by all providers, especially those who care for pediatric patients. This article explores the natural evolution of the intestinal microbiome from the perinatal period into early childhood, the effect of antibiotics on the microbial ecology, and the implications for future health and disease.