Category: Metabolites

Cancer Metabolites Microbiome Nutrition

Ketogenic diet and ketone bodies enhance the anticancer effects of ...

Limited experimental evidence bridges nutrition and cancer immunosurveillance. Here, the team at IGR Paris shows that ketogenic diet (KD) or its principal ketone body, 3-hydroxybutyrate (3HB), most specifically in an intermittent scheduling, induced T cell-dependent tumour growth retardation of aggressive tumour models.

In conditions in which anti-PD-1, alone or in combination with anti-CTLA-4, failed to reduce tumour growth in mice receiving a standard diet, KD or oral supplementation of 3HB reestablished therapeutic responses. Supplementation of KD with sucrose (which breaks ketogenesis, abolishing 3HB production) or with a pharmacological antagonist of the 3HB receptor GPR109A abolished the anti-tumour effects. Mechanistically, 3HB prevented the ICB-linked up-regulation of PD-L1 on myeloid cells while favouring the expansion of CXCR3+ T cells. KD induced compositional changes of…

Immunity Metabolites Microbiome Nutrition

Ketogenic Diets Alter Gut Microbiome in Humans, Mice

Study Suggests Potential Anti-Inflammatory Properties of Ketone Bodies Via Effects on Gut Microbial Ecosystems

Low-carb, high-fat ketogenic diets, which have attracted public interest in recent years for their proposed benefits in lowering inflammation and promoting weight loss and heart health, have a dramatic impact on the microbes residing in the human gut, collectively referred to as the microbiome, according to a new UC San Francisco study of a small cohort of volunteer subjects.

Additional research in mice showed that so-called ketone bodies, a molecular byproduct that gives the ketogenic diet its name, directly impact the gut microbiome in ways that may ultimately suppress inflammation, suggesting evidence for potential benefits of ketone bodies as a therapy for autoimmune disorders affecting the gut.

In ketogenic diets, carbohydrate consumption…

Cancer Metabolites Microbiome Nutrition

Gut microbiome linked to efficacy of PD-1-inhibitor therapy for solid ...

In patients with solid cancers, the concentration of fecal short-chain fatty acids (SCFA) may be a biomarker of the efficacy of the programmed cell death 1 (PD-1) checkpoint inhibitors nivolumab and pembrolizumab, according to researchers in Japan.

Immune-checkpoint inhibitors have been remarkably effective across multiple cancer types, note Dr. Motoo Nomura of Kyoto University and colleagues in JAMA Network Open. However, for solid cancers the response rate to PD-1 inhibitors has been relatively low, they add.

Thus, a biomarker of efficacy “is critically needed for clinical decision-making,” they say, and the gut microbiome profile could be one such factor.

To investigate, the researchers prospectively studied 52 cancer patients with a median age of 67 years who were scheduled to be treated with nivolumab or pembrolizumab. Concentrations…

Cancer Immunity Metabolites Microbiome Nutrition

Gut microbiome regulates the intestinal immune system

A new study in mice unveils the role of vitamin A in immune system regulation, a finding that could assist in developing treatments for autoimmune and inflammatory diseases as well as vitamin A deficiency.

PROVIDENCE, R.I.  — Scientists have long known that bacteria in the intestines, also known as the microbiome, perform a variety of useful functions for their hosts, such as breaking down dietary fiber in the digestive process and making vitamins K and B7.

Yet a new study unveils another useful role the microbiome plays. A team of researchers from Brown University found that in mice, the gut microbiome regulates the host’s immune system — so that rather than the host’s defense system attacking these…

Metabolites Microbiome Nutrition

Druglike molecules produced by gut bacteria can affect gut immune ...

Stanford researchers found that manipulating the gut microbe Clostridium sporogenes changed levels of molecules in the bloodstreams of mice and, in turn, affected their health.

Here’s some food for thought: When you lick your Thanksgiving plate clean this week, you’re not just feeding yourself; you’re also providing meals to the trillions of microbes that live in your gut. And if your dinner includes turkey, a notoriously rich source of the amino acid tryptophan, the gut bacterium Clostridium sporogenes will have the job of breaking down that tryptophan. Then the molecules that are produced by the microbe will flow into your bloodstream in the same way a prescription drug might, interacting with your immune system and changing the biology of the intestines.

Stanford University School of Medicine researchers…

Immunity Metabolites Microbiome Nutrition

Every meal triggers inflammation

When we eat, we do not just take in nutrients – we also consume a significant quantity of bacteria. The body is faced with the challenge of simultaneously distributing the ingested glucose and fighting these bacteria. This triggers an inflammatory response that activates the immune systems of healthy individuals and has a protective effect, as doctors from the University and the University Hospital Basel have proven for the first time. In overweight individuals, however, this inflammatory response fails so dramatically that it can lead to diabetes.

It is well known that type 2 diabetes (or adult-onset diabetes) leads to chronic inflammation with a range of negative impacts. A number of clinical studies have therefore treated diabetes by impeding the over-production of a substance involved…