We are what we eat; fruits and veggies crucial for a healthy gut

If one were to ask a medical student 50 years ago, “What is the main function of the gastrointestinal tract?”, the answer would be simple: to help us digest, absorb and eliminate our food. 

Today’s medical student will know better. Words like “dysbiosis,” “leaky gut,” “gut-brain-axis,” and “immune organ” are not only familiar these days, but also better understood and accepted by traditional, evidence-based doctors. These allopathic physicians have arrived at the “party” of celebrating the immunological role the gut plays via a balanced, rich gut microbiome.

Dysbiosis refers to a disruption or imbalance of the normal repertoire of bacteria and other microbes in the bowel — the amount of healthy bacteria (gut microbiome) matters a great deal. 

Between 1976 and the early 21st century, the key role of the gut microbiome was more familiar in alternative and complementary medical communities. More traditional doctors were leery and wanted more evidence. These days, most pediatricians recognize the importance of optimizing the gut microbiome and preventing dysbiosis in conditions such as eczema, asthma, allergic rhinitis, functional abdominal pain, constipation, diarrhea, reflux, obesity, and diabetes.

In adult medicine, Dr. Will Bulsiewicz, a gastroenterologist and popular guest on podcasts such as Rich Roll Podcast, is seen as one of the world’s foremost experts on this topic.  In his new book, Plant Powered Plus, Bulsiewicz explains in detail how chronic inflammation in our bodies is rooted, in part, via the gut.

For example, when the gut microbiome is not well (dysbiosis), it sets up damage to the gut barrier and, via a leaky gut, pro-inflammatory processes are started, which in turn lead to allergies, auto-immune disorders, cardiovascular disease and neurodevelopmental delays.

Antibiotics are notorious disruptors of the gut microbiome, and alternative medicine practitioners who were upset that some doctors were over-prescribing antibiotics now feel vindicated. Antibiotics are life-saving when used appropriately, and the vilification is targeted at the inappropriate use.

The medical community and pediatricians, in particular, now understand way better than 50 years ago that frequent use of antibiotics disrupts the bowel bacteria.  The use of probiotics after a course of antibiotics is suggested by some. But is ingesting the ideal food not better than buying expensive probiotic supplements? 

Eating foods with more fibre and prebiotics (legumes) plus ingesting more fermented foods such as yogurt, kefir and sauerkraut have been shown to be more efficient than probiotic supplements. The problem in pediatrics is that many children have parents who get tired of fighting with the child to eat more fibre-rich fruits and veggies — foods that counteract dysbiosis.

Two books on picky eaters remain forever popular: The Sneaky Chef and Deceptively Delicious. (Note the words sneaky and deceptive.) 

I have discovered that these books are helpful, but ultimately early introduction to a variety of obvious fruits and vegetables sets the stage for a healthy immune system via the bowel. And just as we condition muscles, we can condition a child’s taste buds by being intentional and consistent from a young age. 

What is difficult to change is the number of cesarean sections. These procedures save lives when done appropriately. But the problem is that the birth process is sterile, and colonization of the skin and gut with bacteria from the mom doesn’t take place. Vaginal births allow for the bathing in and exposure to the mom’s bacteria. 

The mom’s skin matters a lot. For example, if a baby is fed expressed breast milk, that milk contains fewer bacteria to colonize the baby’s bowels than actual breastfeeding. The idea is that the baby’s mouth making contact with the nipple and the areola (skin immediately around the nipple) creates a wider range of good bacterial ingestion. 

Processed and ultra-processed foods are far more commonly consumed than fruits, vegetables, whole grains, fibre and foods rich in polyphenols (bright coloured fruits and vegetables). We are more aware of how this may cause dysbiosis and lead to obesity in children. 

These unhealthy foods set up our immune system at an early age to be more pro-inflammatory and may lead to a higher risk of allergies and autoimmune disorders.

As is the case so often in medical science, things are multi-layered and nuanced. Food plays a major part in ensuring a healthy gut microbiome. Other factors also play important roles, such as stress, ingesting food with unhealthy chemicals and microplastics, and not paying attention to our circadian rhythm.

The interconnectedness of all the above factors is especially appreciated by functional medicine and lifestyle medicine —two disciplines which have become increasingly popular as residencies for younger physicians to pursue. 

Meanwhile, our ancestors who knew that fruits and vegetables are healthy, and fibre is essential, were 100 per cent correct. They just did not appreciate the nuanced science of why that is so. Now we know better!

Dr. Nieman is the founder of Centre 70 Pediatrics. He is a marathon runner and author of three books: Moving Forward, 101 Finish Lines and Sustained.