Some forms of diet may increase levels of harmful bacteria in the gut

 

The type of diet adopted influences the make-up of the gut microbiome, according to a new study into the microbiota of the human gut. Scientists have demonstrated the extent that a very low calorie diet can alters the composition of the organisms present in the gut.

 

While there is a clear association with certain bacteria and disease within the human body, microbiome research remains cutting edge as scientists seek to figure out the myriad roles of bacteria in the body.

 

With the specific diet centric study, the Charité -- Universitätsmedizin Berlin research highlighted a specific risk factor whereby dieting was found to be associated with a rise in levels of the anaerobic bacterium Clostridioides difficile, an organism linked to diarrhea and colitis.

 

While C. difficile can become established in the human colon without causing disease, what is important is the balance of this organism relative to more benign species and the population dynamics should other organisms decrease in numbers.

 

The research looked at 80 post-menopausal women, classed as being slightly overweight to severely obese. The women were studied over the course of 16 weeks.

 

The women followed a medically supervised meal replacement regime of less than 800 calories a day or they eat what they chose and maintained their weight for the duration of the study. To assess microbiome fluctuations, stool sample analysis was performed.

 

The stool samples revealed that dieting reduced the variety of microorganisms present in the gut and generally lowered numbers. Furthermore, the bacteria present in the gut adapted their metabolism so they absorbed more sugar molecules.

 

For those dieting, the researchers recorded a rise in the colonization of C. difficile. This has an association with severe inflammation of the gut wall when the bacterial population is high. Moreover, C. difficile produces toxins which can be harmful.

 

Furthermore, the organism was found to sometimes prevent the absorption of nutrients into the gut wall suggesting a potential association with problems achieving the desired with loss and also with diabetes.

 

The data could be used for new advice when it comes to dieting. For example, the consumption of particular types of food could trigger shifts in existing host bacterial genera. These bacteria may have the ability to affect host immune and metabolic parameters.

 

It should be possible to counterbalance the effects seen in the study with more controlled diets. Evidence suggests that diet can modulate host-microbe interactions and this heralds a promising therapeutic approach.

 

The research appears in the science journal Nature, titled “Caloric restriction disrupts the microbiota and colonization resistance.”

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)