Gut microbiome modulates response to anti–PD-1 immunotherapy in melanoma patientsGood bacteria help fight cancer Resident gut bacteria can affect patient responses to cancer immunotherapy (see the Perspective by Jobin). Routy et al. show that antibiotic consumption is associated with poor response to immunotherapeutic PD-1 blockade. They profiled samples from patients with lung and kidney cancers and found that nonresponding patients had low levels of the bacterium Akkermansia muciniphila . Oral supplementation of the bacteria to antibiotic-treated mice restored the response to immunotherapy. Matson et al. and Gopalakrishnan et al. studied melanoma patients receiving PD-1 blockade and found a greater abundance of “good” bacteria in the guts of responding patients. Nonresponders had an imbalance in gut flora composition, which correlated with impaired immune cell activity. Thus, maintaining healthy gut flora could help patients combat cancer. Science , this issue p. 91 , p. 104 , p. 97 ; see also p. 32
Dietary fiber and probiotics influence the gut microbiome and melanoma immunotherapy responseGut bacteria modulate the response to immune checkpoint blockade (ICB) treatment in cancer, but the effect of diet and supplements on this interaction is not well studied. We assessed fecal microbiota profiles, dietary habits, and commercially available probiotic supplement use in melanoma patients and performed parallel preclinical studies. Higher dietary fiber was associated with significantly improved progression-free survival in 128 patients on ICB, with the most pronounced benefit observed in patients with sufficient dietary fiber intake and no probiotic use. Findings were recapitulated in preclinical models, which demonstrated impaired treatment response to anti–programmed cell death 1 (anti–PD-1)–based therapy in mice receiving a low-fiber diet or probiotics, with a lower frequency of interferon-γ–positive cytotoxic T cells in the tumor microenvironment. Together, these data have clinical implications for patients receiving ICB for cancer.
Trends in meat consumption in the USAOBJECTIVE: To characterize the trends, distribution, potential determinants and public health implications of meat consumption within the USA. DESIGN: We examined temporal trends in meat consumption using food availability data from the FAO and US Department of Agriculture (USDA), and further evaluated the meat intake by type (red, white, processed) in the National Health and Nutrition Examination Surveys (NHANES) linked to the MyPyramid Equivalents Database (MPED). RESULTS: Overall meat consumption has continued to rise in the USA and the rest of the developed world. Despite a shift towards higher poultry consumption, red meat still represents the largest proportion of meat consumed in the USA (58 %). Twenty-two per cent of the meat consumed in the USA is processed. According to the NHANES 2003-2004, total meat intake averaged 128 g/d. The type and quantities of meat reported varied by education, race, age and gender. CONCLUSIONS: Given the plausible epidemiological evidence for red and processed meat intake in cancer and chronic disease risk, understanding the trends and determinants of meat consumption in the USA, where meat is consumed at more than three times the global average, should be particularly pertinent to researchers and other public health professionals aiming to reduce the global burden of chronic disease.