High-fat, low-carbohydrate ketogenic diets have been found to alleviate experimental colitis in rodents. These diets lead to increased endogenous production and utilization of ketone bodies, such as β-hydroxybutyrate (BHB), and supplementation with exogenous ketones has arisen as a potential alternative to ketogenic diets. This study aimed to investigate how continuous high-dose feeding with free acid BHB influences experimental colitis compared to a ketogenic diet with the hypothesis that BHB would also alleviate the inflammation. We fed nine-week-old C57BL/6 J male mice for four weeks with one of three diets: a low-fat control diet, a ketogenic diet, or a low-fat diet supplemented with free acid R-BHB and then induced colonic inflammation with dextran sodium sulfate (DSS). We assessed macroscopic and histological changes in the colon, intestinal permeability to fluorescein isothiocyanate dextran, colonic mRNA expression of tight junction proteins and inflammatory markers, fecal calprotectin, and microbiota composition. While the ketogenic diet alleviated DSS-induced weight loss, macroscopic changes, and histological lesions, the BHB-supplemented diet did not have the same effect. The pre-DSS composition of the microbiota was drastically different between the diet groups which may partly explain the different outcomes. In conclusion, high-dose supplementation with free acid BHB may not produce the same benefits as ketogenic diet in the context of colonic inflammation. • Ketogenic diet (KD) protected from dextran sodium sulfate-induced colitis in mice • Protective effect was not recapitulated by β-hydroxybutyrate (BHB) supplementation • KD resulted in notably different fecal microbiota profile than BHB supplementation • Changes in microbiota may partly explain the different outcomes

BackgroundThe global population is aging rapidly, which is associated with an increase in chronic diseases. One of the possible underlying causes of these chronic diseases is inflammaging, characterised by the general low-grade inflammation that occurs in the body as we age. However, it is unclear to what extent this concept is already being considered as a base for prevention or therapy. MethodsIn this study, the willingness of practicing dietitians in the Netherlands to apply interventions targeting inflammaging was evaluated. Beforehand, a literature study was executed to identify possible parameters for intervention, covering most nutritional, biological, and medical aspects related to inflammaging. Based on the findings of the literature study, dietitians were asked about their awareness of the concept, the willingness to adopt more knowledge, and practical approaches regarding their clients. Results:It was found that of the 56 surveyed dietitians, approximately two-third were already aware of the concept, and among this group, another two-third indicated that inflammaging plays a role in their provision of dietary advice. Generally, the information provided by the dietitians was in line with what was identified in literature. ConclusionsAs a first pilot, it appears that dietitians recognise the impact of nutrition and lifestyle factors on the progression of inflammaging. The willingness to adopt evidence-based practices signifies the importance of continued education and professional development in this area. Eventually, focusing on inflammaging in policy making could be a supporting factor for healthcare systems in the shift from curative to preventive care.