Potential factors in decreased microbial community:
- Formula fed as opposed to breast fed- Breast milk contains microbes which can colonize the newborns body or act as a microbiome while they are still developing. Moving to formula feeding reduces this exposure.
- Caesarean section delivery- C section delivery bypasses the vagina, which contains many microbes.
- Poor diet- Diet has a huge effect on your microbiome and will determine which microbes are able to thrive. Logically this makes sense as your diet will provide for the microbes who live in you. As a specific example, a study mentioned in the Vieira et al. review showed that a diet lacking in plant derived substances will alter the type of bacteria present in the gut.
- Overuse of antimicrobial agents- Increased sanitation overall will lower our exposure to microbes as surfaces simply have less bacteria on them. This means we are picking up less and less microbes throughout our lives.
- Early antibiotic use- Antibiotic use in kids can have harmful long term effects wherein an attack occurs on their microbiome early on and it may never fully recover.
- Extended antibiotic use- If antibiotic tracks are used for too long, resistance can increase in microbes that still survive, as they tend to replicate quickly. This facilitates greater antibiotic resistance in microbes as well, another pressing health issue.
- Lack of human contact- Smaller overall family size or home schooling will result in less human contact. Humans transmit microbes to each other, as we know from infectious diseases being common. Thus, lower human contact will result in reduced microbe exposure.
- Lack of animal contact- With much the same reasoning as above, lack of animal and dirt contact will confer less microbes.
- Loss of microbes in previous generation (vertical transfer)- With the widespread use of antibiotics and sanitation being much increased, certain microbes are rapidly disappearing. Less microbes is harmful for an individual but the effects do not stop there as when they lose microbes they also lose the ability to transfer them.
- Clean drinking water- Although the widespread availability of clean water would be regarded as a good thing by most, it certainly contributes to decreased microbe exposure. This is another logical association. The less microbes in our water, the less microbes that we consume and thus the less we are exposed to.
