November 15, 2019

expert reaction to study on ketogenic diet and flu response in mice

Research, published in Science Immunology, reports on a relationship in mice between a ketogenic diet and the response to influenza infection.

Dr Elma Tchilian, Group Leader Mucosal Immunology, The Pirbright Institute, said:

“This paper emphasises that in this particular strain of mice there are other protective mechanisms against influenza infection in addition to the traditional targets for vaccine development, neutralising Ab and conventional T cells. As the ketogenic diet has many potential side effects, the induction of γδ T cells by other mechanisms may be a promising strategy for protection against influenza infection.”

 Dr Jenna Macciochi, Lecturer in Immunology, University of Sussex, said:

 “Overall the press release does accurately reflect the science. This research explores how just by switching to different energy sources, mammals can tolerate the inflammatory response that results from the body fighting the infection.

“The study appears to be a solid mechanistic study in an in vivo (animal) model of influenza infection with appropriate controls and statistical evaluation.  The mouse models and techniques used are standard for this type of investigation. This work builds on earlier studies showing that specific macronutrient restriction in mice can contribute to better disease outcomes during infection by limiting the destructive inflammatory response.  For example restriction of carbohydrates in the study by Medzhitov and colleagues in 2016 (Wang. Cell.2016 Sep 8;166:1-14.).  It also builds on the emerging field of immunometabolism whereby in the last 5 years, researchers have noted that symptoms of immune-mediated diseases can be manipulated by changing the quantities of the 3 macronutrients (proteins, fats and carbs) in both mice and humans.  And the work on fasting (known to produce ketones which are thought to be acting in a protective way in this study) in protecting from inflammatory damage by Longo and others (ref ref).

“Although the authors have made obvious efforts to delineate the mechanistic link, there are some important considerations, namely that mice and humans are different metabolically.  In addition, humans and mice do not have equivalent populations of gamma deltas T cells which limits the translatability of the findings to humans.

“Though this study further adds to the growing scientific literature that dietary manipulation of the 3 macronutrients (protein/carbs/fats) represents a novel avenue to treat inflammatory conditions, it’s too early to speculate on what this may look like for humans. I think the authors are careful not to overstate the implications of their findings for humans. Since 2016 it has been known for the past few years that there may be a thread of scientific truth to the old adage “feed a cold, starve a fever”(Wang et al 2006) and this study adds support to this opening up the possibility of ketogenic diets for treatment not only of flu but other conditions where inflammation can cause us collateral damage.”

‘Ketogenic diet activates protective γδ T cell responses against influenza virus infection’ by Emily Goldberg et al. was published in Science Immunology at 19:00 UK time on Friday 15th November. 

Declared interests

Dr Jenna Macciochi: Jenna has no declarations of interest.

None others received.