Breast-feeding allows the infant microbiome to develop in a healthy manner and may protect infants from developing overweight in the future.
However, infants in developed nations like the United States may not receive as many benefits from breast-feeding as infants residing in developing countries. This disparity can be mitigated by supplementation with probiotic supplementation.
“Microbiota shifts have been associated, albeit inconsistently, with obesity in adults, including lower diversity, enrichment of Ruminococcus gnavus and a higher ratio of Firmicutes to Bacteroidetes,” Jessica D. Forbes, PhD, from the University of Alberta’s department of pediatrics, and colleagues wrote. “Breast-feeding is among the most influential factors shaping the infant gut microbiome because breast milk contains prebiotic oligosaccharides and probiotic micro-organisms, including bifidobacteria.”
Forbes and colleagues note that although evidence supports the role of breast-feeding in promoting a healthy infant gut microbiome, there is a lack of understanding regarding the association between breast-feeding, weight gain and the developing microbiota.
To define the relationship between infant gut microbiota, overweight and breast-feeding, Forbes and colleagues conducted a prospective cohort study that included infants and mothers who participated in the CHILD pregnancy cohort. All mothers were recruited between Jan. 1, 2009, and Dec. 31, 2012. The researchers collected data on feeding patterns through maternal and hospital records.
The fecal microbiota of infants were examined using 16S ribosomal RNA sequencing once children reached 3 to 4 months of age, 12 months of age or at both ages. Forbes and colleagues considered infants at risk of overweight if their weight surpassed the 85th percentile for their length.
According to maternal reports, 53.8% of the 1,087 infants included in the cohort were exclusively breast-fed at 3 months of age. Those who were reported to exclusively consume formula were more likely to be at risk for overweight (33.3% vs. 19.2%; adjusted OR = 2.04; 95% CI, 1.25–3.32).
Of those who were exclusively breast-fed, 30.9% had a supplemented diet, which included formula as neonates. Forbes and colleagues observed that infants who had a supplemented diet had fewer Bifidobacteriaceae and more Enterobacteriaceae present in their microbiota profiles at 3 to 4 months of age. This did not affect their risk of overweight.
The diversity in microbiota profiles changed significantly based on feeding practices reported at 6 months of age, especially for infants who were fed with both breast milk and formula. These infants had microbiota comparable to those who were fed exclusively formula with more diversity and enrichment of Bacteroidaceae. Diets that included a combination of complementary foods and breast milk at 6 months contributed to a lower diversity and enrichment of Bifidobacteriaceae and Veillonellaceae, much like those who were exclusively breast-fed.
Despite the healthier microbiota and protective factors associated with breast-feeding, findings presented at Nutrition 2018 demonstrate that children in developed nations do not receive as many benefits by consuming breast milk as infants in developing countries.
Bethany M. Henrick
“Breast milk contains a very high concentration — approximately 15 g/L — of complex sugars called human milk oligosaccharides — or HMOs. These sugars are indigestible by humans much like fiber,” Bethany M. Henrick, PhD, director of immunology and diagnostics at Evolve Biosystems, Inc. and assistant adjunct professor at the University of Nebraska, Lincoln, told Infectious Diseases in Children. “Therefore, we require specialized gut bacteria that contain the proper enzymes to break down these complex sugars and digest them. In turn, these bacteria convert HMOs into nutrients that the infant can utilize, such as lactate and acetate.”
“However, our research and [that of] others have shown that many infants born in developed nations no longer have the beneficial microbes that utilize these sugars due to several generations of C-section delivery, formula feeding and antibiotic use,” she continued. “Because of this, babies in developed countries are often missing out on approximately 15% of the nutrients in breast milk.”
Henrick’s research aimed to observe the influence Bifidobacterium longum subsp. infantis can have on the composition of the infant gut microbiota in the first year of life. She conducted a partially randomized study that included lactation support for mothers and their infants, as well as an activated preparation of B. infantis EVC001 or lactation support alone. Infants who received the preparation consumed a mix of expressed breast milk and the supplement for 21 days beginning 7 days after birth.
Infant stool samples were assessed for bacterial DNA using quantitative PCR and 16S rRNA marker gene sequencing. Furthermore, Henrick examined the presence of fecal endotoxin, short-chain fatty acids and fecal pH.
Rapid colonization with B. infantis was observed in infants receiving B. infantis EVC001 (>1,010 CFU/g feces). This colonization was upheld in infants up to 1 year of age, when breast milk was the predominant source of nutrition.
Infants who were colonized with B. infantis had less relative abundances of Enterobacteriaceae and Clostridiaceae. Fewer of these bacteria were associated with less fecal endotoxin. A significant increase of fecal lactate, acetate, total short-chain fatty acids and lower fecal pH was observed in infants receiving supplementation with B. infantis.
“Do not hesitate to use [B. infantis] for your infant patients. We have 15-plus years of science that clearly indicate that B. infantis has evolved to be the intended colonizer of the breast-fed infant gut, leading to an approximate 80% reduction in potentially pathogenic bacteria and decreased endotoxin production, which is directly linked to inflammation,” Henrick said.
“Babies that are fed [B. infantis EVC001] utilize all HMOs in breast milk and have significantly increased acetate and lactate levels in the stool, both which have been linked to positive health outcomes, as well as a fecal pH that inhibits the growth of pathogenic bacteria,” she added. – by Katherine Bortz
Reference: Henrick BM, et al. Bifidobacerium longum subsp. infantis stably restores the infant gut microbiome over the first year of life in breastfed infants. Presented at: Nutrition 2018; June 9-12; Boston.
Disclosures: Forbes does not report any relevant financial disclosures. Henrick is an employee of Evolve Biosystems. Please see the full study for other authors’ relevant financial disclosures.