Will Bulsiewicz, M.D. is a respected gastroenterologist who wrote “Fiber Fueled.” Today’s column is based on this book.

For centuries, physicians looked at bacteria as harmful — causing wound infections, and diseases such as pneumonia and meningitis. Starting with the discovery of penicillin in 1928, multiple antibiotics were developed to fight against bacteria. There definitely are harmful bacteria, and — although over-prescribed — antibiotics have saved millions of lives. However, it turns out that there are also beneficial bacteria.

Prior to 2006, scientists were aware of about 200 species of bacteria in our colon, but assumed they were “just along for the ride” and that they didn’t contribute to human health. Because most gut bacteria didn’t grow on traditional culture plates, they were not studied extensively until a laboratory breakthrough in 2006. Now, over 15,000 species of gut bacteria have been identified, and it’s estimated that there are at least another 20,000 that haven’t been identified yet. Thousands of scientific papers have been published about the gut microbiome.

As Dr. Bulsiewicz puts it, “when things are working the way they’re supposed to, we have a diverse, abundant [some 39 trillion!] community of microbes living in harmony in our colon.” These bacteria “eat what we eat,” and if we eat the right food, our microbiome supports immunity, metabolism, hormonal balance, cognition, mood, and gene expression. If we eat unhealthy food, the gut microbiome becomes dysfunctional — a condition called “dysbiosis.” Following are common symptoms associated with dysbiosis:

Gastrointestinal: abdominal pain or cramping; gas and bloating; food sensitivities and allergies; diarrhea and constipation; mucus in stool; nausea and indigestion; GERD (gastroesophageal reflux disease).

Extraintestinal: weight gain, fatigue, brain fog; moodiness; anxiety; joint and muscle aches; weakness; bad breath.

Below are common medical conditions in which dysbiosis plays a role:

Immune-mediated conditions: type 1 diabetes; celiac disease; multiple sclerosis; asthma; food allergies; eczema; seasonal allergies; psoriasis; scleroderma; chronic fatigue syndrome; Sjorgren’s syndrome; rheumatoid arthritis; ulcerative colitis and Crohn’s disease; lupus; sarcoidosis; fibromyalgia.

Metabolic conditions: obesity; type 2 diabetes; atherosclerosis/heart attacks and strokes; high cholesterol; chronic kidney disease; gout; fatty liver disease; pancreatitis.

Endocrine and hormonal conditions: endometriosis; polycystic ovary syndrome; female infertility; sexual dysfunction; hypothyroidism; breast, prostate, and endometrial (lining of the uterus) cancer.

Neuropsychiatric conditions: Alzheimer’s; Parkinson’s; schizophrenia; ADHD; ALS; anxiety and depression; autism; bipolar disorder; migraine headaches; restless leg syndrome.

For additional information read Dr. Bulsiewicz’s book, available on Amazon, or go to his Instagram account:  @theguthealthmd.

Dr. Greg Feinsinger is a retired family physician who started the non-profit Center For Prevention and Treatment of Disease Through Nutrition. For questions or to schedule a free consultation about nutrition or heart attack prevention contact him at gfmd41@gmail.com or 970-379-5718.