Gut Microbiome

Our guts are home to millions of microbes. These microbes help our bodies do important tasks like digesting food, fighting diseases and making vitamins. The type of microbes present in our gut depends on factors like diet, the use of medications, and sanitation practices. Research shows the diversity of the microbes living in our gut is decreasing, especially as countries become more developed. For example, stool samples from rural Papua New Guineans contain an additional 50 species not found in people living in the United States. What has caused the disappearance of L. retueri is currently unknown. However, it is known that in order to help this species to grow specific types of carbohydrates need to be consumed. People in North America eat much less of these carbohydrates compared to rural Papua New Guineas. Examples of foods containing these carbohydrates include yams, beans, and artichokes. It may be possible for L. reuteri to live in the human gut if it is taken as a probiotic and a diet containing the types of foods which helps it grow is eaten. Furthermore, if L. reuteri can be re-established, it may have beneficial effects on how our immune system works. The investigators hypothesize that L. Reuteri can be re-established in the gut of Canadians when they are fed a diet containing the types of foods known to help it grow. To test this hypothesize, the survival of two strains of L. Reuteri in the gut of Canadians will be compared when they eat their usual diet, to when they eat a diet containing the types of food known to help L. Reuteri survive. We will measure the amount of L. retueri present in stool samples of participants, and measure changes in metabolic and immune markers that occur as a result of the intervention. This study will help determine if a 'lost' species can be reintroduced into the human gut, and if this is associated with immune and metabolic health.