The microbiome
Microbes can be found in our skin, nose, mouth, and gut because they live with us. Every human being’s microbiota is unique, like a fingerprint that can be used for identification methods. Research has shown that identifying people from their microbiome is feasible, at least for short periods, like a year.
During childbirth, the mother “seeds” her child’s microbiome. The types of microbes passed on dependent upon the mode of delivery, such as premature birth, cesarean section, and vaginal delivery. The initial differences in microbiota can be associated with allergies and obesity later in life.
Mother’s milk plays an essential role in establishing infant gut microbiota because it has nutrients for both the child and its microbiota. Oligosaccharides, a sugar found in a mother’s milk, is considered a food or prebiotic for microbiota. Moreover, a breastfed child has different types of microbes from that of a bottle-fed child. Microbes diversify and grow with the child as they age and eat a variety of food. While our microbiome tends to stabilize after age 2 or 3, different environmental and dietary factors alter the microbiome over time.
- Stress can affect gut motility and gastrointestinal secretion. In a stressful environment, hormones like cortisol and norepinephrine can create an imbalance of good and bad bacteria.
- Diet is vital in determining the types of microbiota that live in the colon. A diet based on a variety of food choices can lead to diverse microbiota. Gut microbes increase with a high fiber diet because dietary fiber provides them beneficial nutrients. High fat and low fiber diets are linked to a decrease in overall total bacteria and valuable species.
- Exercise is associated with increased diversity and abundance of gut microbiota. A review of activity on the microbiome found, “both diet and exercise determined the microbial biodiversity of the gut." Exercise shifts the microbiome towards that seen in leaner animals, in this case, mice, on the same diet.
- Medications like antibiotics alter the gut microbial composition and diminish taxonomic diversity. This is true for humans of all ages.
The microbiome also plays a role in digesting our food and boosting mental and physical health throughout our lives.
- The Hygiene Hypothesis suggests that childhood exposure to multiple germs and infections helps develop a robust, resilient immune system.
- Intestine microbiota produces critical vitamins, including vitamin B12, Thiamine and Riboflavin, and K, necessary for good health.
- Our brain and gut are in constant communication through neurotransmitters. Approximately 90% of the body's serotonin which regulates mood, appetite, digestion, and sleep, is made in the digestive tract by specific microbes. A healthy gut not only keeps the digestive system working properly but also promotes a stable mood, happiness, and a stronger memory.
- The lack of diversity of bacteria present in our colon has been associated with bowel-related disorders such as irritable bowel syndrome (IBS). Several studies have demonstrated differences in the gut microbiome composition in patients with IBS compared with healthy controls. Whether the changes were a cause or a result of the disease is unclear.
Metrics of change
Hundreds of different species exist within our microbiome. In general, a more diverse set of bacteria is better than a less diverse set. Scientists study the microbiome’s bacterial communities using metagenomics. Genetic material is collected and the DNA sequenced through computer programing to count the number of bacterial species and record the abundance of each type. An imbalance of microorganisms is called dysbiosis.
In one study, differences in the microbiome of children fed a western diet (European children) were compared to children with a fiber-rich diet (Burkina Faso). Metagenomic analysis indicated the abundance of two types of microbes; the increase of one microbe over the other, probably driven by their Western diet, might predispose them to future obesity.
Taking care of your microbiome
We should take care of the microbiome, like we would a pet, and feed them properly for our benefits and theirs.
- Feed them their foods, the prebiotics, by including them in your diet. Prebiotics are found in fiber-rich food like asparagus, oatmeal, Jerusalem artichokes, pulses, and bananas. A study on young children showed that prebiotics reduced diarrhea, vomiting, and fever significantly.
- Probiotics are “live microorganisms which when administered in adequate amounts confer a health benefit on the host.” Ensure probiotics are in your diet – sourdough bread, fermented vegetables like kimchi or sauerkraut, and dairy products like yogurt and aged cheeses are good sources of probiotics.
- Let children help in the garden and play with pets expose them to diverse microbial communities.
- Avoid unnecessary antibiotics.
- Avoid stress, the enemy of gut health.
- Stress and gastrointestinal distress are bidirectional. Just as GI symptoms can “stress you,” stress can trigger and worsen gastrointestinal problems.
