Gut Bacteria: Starve or Feed?

Dr. David Wiss

July 10, 2021

Gut Health

Gut-related health problems are on the rise. Whether it be inflammatory bowel diseases (IBD) such as ulcerative colitis or Crohn’s disease; irritable bowel syndrome (IBS), which covers a range of abnormalities with unknown etiology; small intestinal bacterial overgrowth (SIBO); increased intestinal permeability (“leaky gut”); or general dysbiosis (imbalance in gut bacteria), people are searching for answers, particularly in the domain of mental health. 

Many of these conditions require medical diagnosis and intervention, while others can be managed with nutrition and lifestyle. Lifestyle medicine interventions for anxiety are on the rise. Importantly, conditions such as leaky gut have also been associated with various metabolic diseases [1], which often require their own medical and dietary interventions.

There are many different approaches to treating gut-related issues, which depend on their diagnosis and the practitioner's training (and bias). For example, a gastroenterologist, an acupuncturist, and a registered dietitian nutritionist might have differing opinions on how to best treat SIBO. 

Loosely defined gastrointestinal issues such as IBS or leaky gut have even more variation in treatment approaches because they are challenging to diagnose and can have many possible causes. While some medications and supplements can be helpful, no nutritional strategy has been formally standardized. Practitioners also seem to disagree on the clinical utility of testing for food sensitivity, which can also be linked to gut microorganisms [2].

Most practitioners agree that the primary goal is to improve the health of the “second brain” by increasing bacterial diversity thereby increasing the production of short-chain fatty acids. This may take some time and may require functional medicine tests such as stool analysis, or in some cases food sensitivity testing (blood test). While functional nutrition approaches strongly favor elimination diets, others believe in building a second brain through the strategic introduction of specific foods (rather than elimination). 

For many gut-related problems, some practitioners use an elimination (“starve”) approach where entire food groups or foods with certain fibers (e.g., FODMAPs) are removed. The rationale is that opportunistic bacteria are relying on these foods/fibers, and therefore need to be starved for symptom relief. In many cases, this is the only approach that provides comfort. After elimination, there are protocols for the reintroduction of some foods. 

One problem with this approach is that many patients associate the eliminated food (e.g., whole grains, beans, or certain vegetables) with the discomfort they are trying to avoid. As a result, many people stay on restricted diets and never properly reintroduce them to strengthen their gut. This limited diet can have adverse effects on the gut long-term, where it can become even more difficult to tolerate certain foods. The reintroduction process is critical to balancing out the gut microbiota.  

Another approach (“feed”) is the opposite of elimination: instead of starving the “bad” bacteria, the emphasis is on feeding the beneficial microbes. This approach may include high-dose probiotics, prebiotic supplements, and higher-than-average amounts of dietary soluble fiber. This approach also has shortcomings: the high-fiber diet to a weakened gut can be very uncomfortable for some people and, in some cases, this will not resolve without changing the course of treatment.  

In other instances, persistent feeding of the beneficial microbes will eventually shift the inner ecosystem in ways favorable to gut health over the long run. The “feed” approach will often require long-term probiotics (and in some cases short-term digestive enzymes). Thus, it becomes imperative to maintain a diet high in prebiotic fibers and polyphenols [3], and this may require eating foods that the individual has never eaten or enjoyed before. Nutritional variety is critical and has important implications for one’s relationship with food (nutritional psychology). 

So which approach is right for you? Team Starve or Team Feed? At Wise Mind Nutrition, we are here to ask the right questions to help you find the best answers. It might be a combination of the two approaches. It might depend on whether there is a history of a restrictive eating disorder. Some trial-and-error is likely to be necessary. It is important to consider if the gut issues have emerged recently or if they can be traced back to early postnatal years [4]. 

Wise Mind Nutrition operates at the intersection of the gut and brain. We are here to keep you up to date with the latest science on gut health and nutritional psychiatry. Be here for it!


1. Chakaroun RM, Massier L, Kovacs P. Gut Microbiome, Intestinal Permeability, and Tissue Bacteria in Metabolic Disease: Perpetrators or Bystanders? Nutrients. 2020;12(4):1082.

2. Caminero A, Meisel M, Jabri B, Verdu EF. Mechanisms by which gut microorganisms influence food sensitivities. Nat Rev Gastroentero. 2018;16(1):7–18.

3. Vancamelbeke M, Vermeire S. The intestinal barrier: a fundamental role in health and disease. Expert Rev Gastroent. 2017;11(9):1–14.

4. Jena A, Montoya CA, Mullaney JA, Dilger RN, Young W, McNabb WC, et al. Gut-Brain Axis in the Early Postnatal Years of Life: A Developmental Perspective. Frontiers Integr Neurosci. 2020;14:44.