What is already known
Mode of delivery, antibiotic use and feeding method can influence the infant microbiota, which is mostly acquired from the mother. However, it’s unclear whether westernized lifestyles, with processed foods and high-calorie diets, also regulate the transmission of gut microbes from mothers to infants.
What this research adds
Researchers assessed the gut microbiota of 25 pairs of mothers and infants from Ethiopia and compared them with the microbiotas of four other mother-infant groups with different lifestyles — either westernized and non-westernized. Compared to infants from westernized populations, Ethiopian and other non-westernized newborns shared a smaller fraction of the microbiota with their mothers, likely because some of the infants’ gut microbes are acquired through the consumption of local fermented foods. The microbiota of Ethiopian newborns was more diverse than that of westernized populations, and it included previously uncharacterized species belonging to the Selenomonadaceae and Prevotellaceae families.
Conclusions
The findings suggest that lifestyle can influence how bacterial strains are shared between mothers and infants.
The microbiota of westernized populations differs from that of non-westernized ones. New research may explain why: lifestyle factors, including processed foods and high-calorie diets, may influence how gut bacteria are shared between mothers and infants in the first months of life.
The findings, published in Current Biology, highlight the importance of diversifying participants of microbiota studies according to geography and lifestyle and intensifying research efforts on maternal-infant gut microbiota transmission.
Scientists have known that mode of delivery, antibiotic use and feeding method can influence the infant microbiota, which is mostly acquired from the mother. However, it’s unclear whether westernized lifestyles, with processed foods and high-calorie diets, also regulate the transmission of gut microbes from mothers to infants.
To address this question, researchers led by Edoardo Pasolli at the University of Naples Federico II, Maria Carmen Collado at the Institute of Agrochemistry and Food Technology in Valencia, and Nicola Segata at the University of Trento assessed the gut microbiota of 25 pairs of mothers and infants from Ethiopia. Then, the researchers compared these microbiotas with those of four other mother-infant groups with different lifestyles — either westernized and non-westernized.
Uncharacterized species
The microbiotas from westernized and non-westernized newborns overlapped during the first months of life more than they did later in life, likely reflecting similar initial breast-milk-based diets.
However, the composition of the gut microbiota of Ethiopian infants differed from that of westernized populations. Bacteria including Clostridium innocuum, Ruminococcus gnavus and Eggerthella lenta were associated with European populations, whereas microbes such as Prevotella copri, Prevotella stercorea and Ligilactobacillus ruminis were mostly found in Ethiopian microbiotas.
Several previously uncharacterized species were found in Ethiopian and other non-westernized infant microbiotas, with most of the strains shared between Ethiopian mothers and their infants being from uncharacterized species belonging to the Selenomonadaceae and Prevotellaceae families.
Food influence
Further analyses suggested that locally produced food made from teff could be the source of some of the unusual species that were detected in Ethiopian populations. Teff is a major food grain in Ethiopia, where it is used to make a fermented bread-like food and other products that are traditionally eaten by new mothers and weaning infants.
“This is the first study addressing mother-infant strain sharing in non-westernized communities and reporting how environmental conditions affect not only infant microbiome composition but also its acquisition,” the researchers say.
However, more work is needed to understand the impact of uncharacterized bacterial strains on infant colonization and development in non-westernized populations. “These preliminary findings on mother-infant strain sharing strongly support the need for a more comprehensive understanding of maternal transmission in light of geography and lifestyle,” the authors say.
