dietary protein

Different diets can affect C. diff infection and survival

We’ve covered the topic of Clostridium difficile infection extensively on this blog. We know that infection of this bacteria (CDI) can be nasty, sometimes even leading to death. A lot of research has been done to find ways to treat the effects of C. diff infection or to find out how the infection is acquired, but few papers have investigated dietary interventions to help treat CDI.  A new study published by PLoS One examined this, studying how different diets, and specifically how protein content of those diets, affected the severity of CDI.

          7-8 week old male mice were weighed and separated into five groups, each given a different diet. One group was fed a protein-deficient 2% protein diet, and a counterpart group was fed a 20% protein diet. Another group was given a Research Diets regional basic malnutrition diet, while its counterpart was fed a matched control. A fifth group was fed a traditional (corn, wheat, soybean) diet, and acted as the positive control. Mice were fed the diets 12-14 days before being given antibiotics and then infected by C. difficile.  After infection, the mice were housed individually to prevent being affected by other mice. Stool and colon samples were collected from the mice up to two weeks after infection, and the bacterial content was sequenced.

Mice on the 20% protein diet showed delayed onset disease with a 25% survival rate over 2 weeks. Mice on the 2% diet also showed delayed disease onset and had a survival rate of 57.1% over two weeks. A significant statistically difference in survival and weigh loss was seen between the traditional diet and both the 20% and 2% diets, however the survival difference between the 20% and 2% groups was not significant.

In another part of the study done by the researchers, they chose to examine the presence of four gut microbiota groups ( Firmicutes, Bacteroides, Enterobacteriaceae, and total bacteria), after antibiotics or no antibiotics. All aspect of the experiment were the same except for this one factor. In mice not given antibiotics, the total number of bacteria was greater in the colon of mice given traditional diet. In mice given antibiotics, traditional diet-fed mice had lower levels of Bacteroidetes but higher levels of Firmicutes and Enterobacteriaceae. The most significant finding the researchers may have made however, is that traditional diet-fed and antibiotic given mice had the highest levels of C. difficile and therefore C. difficile toxins.

In the end, it can be assumed that diet does influence rates of C. diff infection. The presence of antibiotics also alters the bacterial compositions of the colon, with lower protein diets seeming to protect against or prevent full potential C. difficile infection.

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