Diet of the mother:
-The diet of the mother during gestation and before pregnancy showed changes in microbial composition in their feces. Obese pregnant women showed significantly more Bacteroides and Staphylococcus in their feces in comparison with normal weight pregnant women. A study of diet induced obese rats revealed that when these rats were fed oligofructose prebitoics during pregnancy and lactation, the cecal microbiome of the offspring was altered. The result was that it prevented increased adiposity in the both the dams and offspring. This implied an early maternal effect on offspring microbiota
Antibiotics:
-Antibiotics given to pregnant mice showed a few negative effects such as decreased bacterial diversity. Researchers also observed that maternal antibiotic administration during pregnancy decrease immune response in the infant mice. Lastly, non-absorable antibiotics given to pregnant maternal mice altered offspring behavior, showing decreased locomotor activity and lower levels of exploratory activity.
Mode of delivery
The type of delivery seems to have an affect on the bacteria that infants are exposed and colonized with when they are first born. The two modes discussed are vaginal vs. Cesarean section birth and how they affect the gut microbiota of an infant. The infants delivered via the vagina displayed colonization of vaginal and maternal gut bacteria in their gut. Infants who were born via C-section were colonized by bacteria that resembled skin and oral microbiota. This is interesting because the microbiome of c-section infants contained a higher proportion of bacterial anti-biotic resistant genes than vaginally delivered infants. It has been suggested that disruption of vaginal bacteria transmission due to C-section can cause long-term medical implications.
Breast Feeding vs Formula:
-Breast milk contains sugars that cannot be digested by infants so bacteria such as Bifidobacterium, Lactobacillus, and Bacteroides help break down the polysaccharides to be used as an energy source. This gives them an advantage over competing bacteria. As a result Bifidobacterium are most abundant in breast-fed infants while Enterococci and Clostridia are dominant in formula fed infants. Three month old breast fed infants had oral bacteria that contained antimicrobial properties that were not found in formula fed infants.