Studies are investigating whether meat- or dairy-based complementary foods affect gut microbiota and growth

The effects of the gut microbiota on human health, including obesity risk, have been analyzed primarily in animal models and adults. Recent studies have shown that early postnatal colonization may play an important role in the establishment and maturation of the gut microbiota. Early complementary feeding (around 5-12 months) is the time to introduce solid foods slowly to the infant rather than relying solely on formula or breast milk. Gut microbiota changes and growth trajectories during such periods have been reported to program body composition, long-term body weight, and disease risk.

study: Differences in Gut Microbiota in US Formula-Fed Infants Consuming Meat- and Dairy-Based Complementary Foods: A Randomized Controlled TrialImage Credit: Lopolo / Shutterstock

A large cohort study showed that deviations from the normal gut microbiota in Malawian infants can cause growth failure. Transplantation from infants to germ-free mice also compromised the mouse phenotype. Two further studies reported slower weight gain in Malawian infants and impaired growth in preterm infants, associated with lower gut microbiota diversity. and in low-resource settings, it is still unclear how complementary diets affect the gut microbiome of infants.

Diet influences the gut microbiota, but few studies have analyzed the effects of solid or complementary foods on microbiota development in infants. It has been reported that a meat-based complementary diet increased the abundance of certain commensal strains compared to a fortified infant cereal-based diet. However, it is not yet known whether such diet-induced alterations in the gut microbiota affect infant growth.

A recent study comparing meat and dairy products as the main source of protein from complementary diets in infants aged 5–12 months reported increased age-specific Z-scores (LAZ) in the meat-eating group. I was. On the other hand, an increase in the length Z-score (WLZ) parameter weight and an increased risk of overweight were observed in the dairy group. Increases in circulating insulin, IGFBP3, and IGF-1 were observed from 6 months to 12 months, whereas he observed no differences between the two groups at 12 or 24 months. Furthermore, no differences were observed between the two groups in the associations of biomarkers or metabolites with infant growth parameters.

new research in the journal The forefront of nutrition science We aimed to analyze the effect of complementary foods on infant gut microbiota development and whether it is related to infant growth.

About research

The study recruited healthy full-term, formula-fed infants and randomly assigned them to receive a dairy- or meat-based complementary diet from 5 to 12 months of age. The meat group consumed pork, beef, and chicken (provided), while the dairy group consumed cheese, yogurt, and whey protein powder (provided). months), at monthly home visits, and at the end of the intervention (12 months). Collection of fecal samples was performed at 5, 10, and 12 months of age with soiled disposable diapers fitted with biodegradable liners.

Bacterial profiles were assessed by DNA extraction from fecal samples, extensive amplification and sequence analysis of the 16S rRNA gene. This was followed by alignment to the human reference genome hg19 using bowtie2 and assessment of fecal short-chain fatty acids (SCFAs) using his Miseq paired-end reads from Illumina.

Investigation result

The results showed that a total of 64 infants completed the study, of which 59 stool samples were collected at baseline, 52 at 10 months and 57 at 12 months. No differences were observed between the two groups regarding sex, length at birth, maternal education, or maternal BMI. Mothers are reported to be obese on average, with a BMI between 25 and 29.9. An increase in LAZ was reported in the meat group compared to the dairy group, whereas WAZ was reported to be increased in both groups.

Both groups showed age differences between 5-10 and 5-12 months of age. However, no significant difference was found between 10 and 12 months. A significant difference in beta diversity was observed at 12 months between the meat and dairy groups. Significant increases in alpha diversity were reported for 5 vs. 10 and 5 vs. 12 month comparisons. Moreover, a significant increase in alpha diversity was observed between 10 and 12 months. Differences in alpha diversity between the two groups were only observed at 12 months.

The four most abundant phyla at all three time points were reported to be Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes. No phylum differences were observed at 5 months between diet groups. However, we observed that Firmicutes abundance increased with time, while Proteobacteria and Actinobacteria decreased. AckermanthiaVerrucomicrobia phylum was reported to be the only taxon with significant group-wise interactions at the genus level. An increase in abundance of this genus was observed with age in the dairy group, whereas a decrease was observed in the meat group.

After adjusting for dietary groups, 17 age-related taxa were reported for all infants. Four out of five different abundant taxa in the Proteobacterial phylum were observed to decrease in abundance with age. In addition, 10 of the 11 his Firmicutes taxa were observed to increase with age. Furthermore, no change was observed in the dairy group, whereas a significant fold change in butyrate was observed in the meat group from 5 to 12 months. and was observed to be negatively associated with WAZ.

Thus, the current study demonstrated that complementary feeding is an important developmental stage for infant growth and gut microbiota maturation. Complementary food choices influence gut microbiota diversity and community constriction, which may affect infant growth. Further research is needed to understand.

Limitations

This study has certain limitations. First, the study sample size was small. Second, the collection of microbiota samples was rare. Third, the study included only formula-fed infants and not a breastfed reference group. Different protein availability and amino acid composition may have different effects on the structure of the gut microbiota.