The WheatFoods Council and ACSM recently hosted an industry-presented webinar with Corrie Whisner, PhD entitled Wheat, Microbiome and Health.

Watch the full webinar here

Several questions were asked by attendees during the webinar and the answers pertaining to Exercise, Diets, and more are below.

Exercise and the Microbiome:

How does exercise affect the gut microbiome? Is the exercise weightlifting or cardio training?

Exercise appears to have an impact on the gut microbiome. Interestingly, the effects of physical activity and exercise seem to be different from those elicited by dietary intake. This means that both diet and exercise are important, and perhaps engaging in only one is not going to get you the health benefits that you want. So far, only self-reported physical activity and aerobic (biking and running) exercise have been evaluated for associations with the gut microbiome. Some studies show lower microbial diversity while others show increased diversity as a result of exercise. We don’t know what this means just yet, but it definitely looks like our microbial passengers also enjoy a little bit of active time each day. Stay on the lookout for more in this exciting area!

Diet: Keto, Vegan and the Microbiome

How does a Keto diet affect bacteria populations and if the effect is negative, is it negative enough to avoid the keto diet altogether?

Keto diets are very high in fat and low in carbohydrates. As a result, they are also often low in dietary fiber, which we know is important for building a healthy gut microbiome. For some individuals, especially those with autism spectrum disorders, ketogenic diets are proving beneficial but careful oversight from a physician and dietitian is needed when carbohydrate levels are very low. Carbs are important for fueling many of the cells in the human body. In fact, glucose is the preferred energy sources of many tissues, meaning that to process and metabolize fat takes more up-front energy and puts extra stress on the body.

When weight loss is attributed to following a keto diet, it is may be the loss of water weight and not real fat losses. While this is often shared on social media and blogs, be wary. Trust your microbes to help in your weight loss endeavors by letting them ferment healthy fiber and polyphenol-rich foods that reduce inflammation throughout the body.

What is your opinion on the pros and cons of a vegan diet?

Vegan diets are one of the few dietary approaches that have never been followed by a large group of people in a society out of necessity.  Nearly all traditional societies have been omnivores, eating both plant and animal foods. Since vegan diets are highly restrictive and require additional nutrient supplementation in order to meet basic requirements, it is hard to consider this eating pattern as a “healthy” approach to eating for most people.  With very careful planning and attention to protein intake, as well as vitamin B12, vitamin D, iron, and calcium, a vegan diet can work.  And, certainly it can be very high in fibers that benefit the microbiome, as can a vegetarian or traditional diet that focuses on getting proteins from plant and animal sources. 

What are your thoughts regarding fasting and modified fasts that proponents argue help to balance out the bacteria in the microbiome if the person's issues stem from SIBO?

Fasting and modified fasts affect all of digestion and metabolism.  Since SIBO is a condition of bacterial overgrowth, fasting might “starve” the bacteria in the small bowel but it also starves ALL of the bacteria in the gut.  Typically, SIBO is treated with a course of antibiotics followed by a diet that repopulates the gut.  It should also be understood that SIBO can arise from a number of conditions that are not dietary:  there are anatomical and other health conditions that can lead to SIBO.  This is definitely something that should be thoroughly checked by a gastroenterologist familiar with this condition.

Is it good for me to eat only veggies as I am vegetarian?

A healthy diet requires foods from all the food groups:  fruits and vegetables, grains and starches, proteins from a variety of sources, calcium sources and healthier fats and oils.

How does a diet such as the Whole 30 or Paleo affect the microbiome?

Any diet that increases fruits, vegetables and fibers from grains and legumes can benefit the microbiome.  To my knowledge, Whole30 allows any “whole” food but Paleo excludes grains and beans.  Both diets exclude dairy which means yogurt and kefir (probiotics) are excluded as well.  Any dietary plan followed for a short while will not have lasting impacts on the microbiome, but eating patterns that exclude dietary fibers and probiotics are not as healthy for the microbiome as other patterns.

Most “Blue zone” regions have mostly plant based diets and little to no dairy. How would you compare their microbiome to the Western diet specifically with dairy consumption?

Blue Zones, where people are reported to live longer and healthier lives, offer a unique glimpse into longevity.  The other longevity factors that have to be considered are the communal support offered in these areas, the shared meals, and the active lifestyle based on natural movement not gyms.  We know that certain gut bacteria respond well to fermented dairy (yogurt and kefir). We also know that a more plant-based diet seems to be a healthier overall approach. Bone health depends on an adequate intake of calcium, vitamin D and perhaps the right luminal acidity from plant fibers.  

Read this journal article for more on Blue Zones (offsite)

Effects of Birth, Geography on the Microbiome:

Are you likely to have more or less microbes if you were delivered by cesarean section?

Babies delivered by C-section seem to have a lower gut microbial diversity, compared to infants delivered vaginally. The members of the gut microbial community also differ with mode of delivery. C-section deliveries tend to result in a gut microbiome in the infant that looks more like the skin community while vaginal deliveries result in greater Bifidobacteria and Bacteroides species. Further, c-section deliveries have been associated with a delayed colonization of Bacteroidetes in infants. How long these differences persist is still under debate but has been reported to last anywhere from 1 to 2 years of age.

Stinson LF, Payne MS, Keelan JA. A Critical Review of the Bacterial Baptism Hypothesis and the Impact of Cesarean Delivery on the Infant Microbiome. Front Med (Lausanne). 2018;5:135. Published 2018 May 4. doi:10.3389/fmed.2018.00135

You mentioned that there is a difference in one's microbiome between someone who was born vaginally vs by c-section. What are the differences? Is one better?

C-section deliveries are life-saving medical procedures that are sometimes needed to protect mothers and infants from dangerous delivery outcomes. Being delivered by c-section has been associated with increased risk for childhood asthma, skin infections, allergies, inflammatory bowel diseases, and type I diabetes mellitus. As a result of these links, vaginal deliveries are better than elected (non-medical need) c-section deliveries. Vaginal deliveries are believed to seed the infant’s gut (sometimes called a bacterial baptism) with vaginal fluid containing beneficial microbes. Specific differences in the abundance of microbial groups include greater Staphylococcus, Corynebacterium and Propionibacterium in babies delivered by c-section and greater Lactobacillus, Prevotella and Sneathia in infants delivered vaginally.

Stinson LF, Payne MS, Keelan JA. A Critical Review of the Bacterial Baptism Hypothesis and the Impact of Cesarean Delivery on the Infant Microbiome. Front Med (Lausanne). 2018;5:135. Published 2018 May 4. doi:10.3389/fmed.2018.00135

Matamoros S, Gras-Leguen Christele, Le Vacon F, Potel G, de La Cochetiere M-F. Development of intestinal microbiota infants and its impact on health. Trends in Microbiology. 2013;21(4):167-173. doi:https://doi.org/10.1016/j.tim.2012.12.001

On the influences of microbes, how exactly is geography responsible?

Geography may influence the microbiome in various ways. For example, individuals who live in rural areas tend to have more diverse gut microbiome communities than those living in urban settings. A recent paper by He et al. in Nature Medicine suggests that geography has important influences on the composition of our gut microbiome, which may provide context for how microbes correlate with disease. This could be useful for identifying more accurate and personalized treatments for individuals with similar conditions living in different locations.

He Y, Wu W, Zheng H-M, Li P, McDonald D, Sheng H-F, et al. Regional variation limits applications of healthy gut microbiome reference ranges and disease models. Nature Medicine. 2018;24:1532-1535.