Fasting and Immune Function

Intermittent fasting is the latest health fad. When I say fad, I mean there are as many definitions of what it means as there are experts. In a recent edition of the journal Cell, three papers were published that provided some insight into the effects of three different types of intermittent fasting on three different systems involved in immune function. That’s our topic of the week. I’ll present each study and comment on the implications on Saturday.

In the first paper, researchers used juvenile mice to examine changes in immune function in sections of the intestine called Peyer’s patches (PP). These patches form an important part of the immune system by monitoring intestinal bacteria populations and preventing the growth of pathogenic bacteria in the intestines. The mice were fasted for 36 hours. Results were compared with normally fed mice that served as controls.

During fasting, immune cells were disrupted and thus compromised the typical immune response; specifically, B cells were sent to bone marrow. It’s difficult to say whether this is a protective mechanism or not. The B cells were returned to the PP during re-feeding. There were many more parts of the study, but the bottom line was that the immune system was compromised during fasting and remained impaired for a time after re-feeding.

We’ll take a look at the second study on Thursday.

What are you prepared to do today?

        Dr. Chet

References:
1. Cell. 2019. DOI:https://doi.org/10.1016/j.cell.2019.07.047.
2. http://bit.ly/2lxYIRa.