We report on a comprehensive analysis of the gut microbiomes of patients with gastrointestinal (GI) cancer receiving anti–PD-1/PD-L1 treatment. The human gut microbiota has been associated with clinical responses to anti–PD-1/PD-L1 immunotherapy in melanoma, non–small cell lung cancer, and renal cell carcinoma. We aimed to investigate this association in GI cancers. We also identified bacterial taxa with patient stratification potential. We recruited 74 patients with advanced-stage GI cancer receiving anti–PD-1/PD-L1 treatment and collected their fecal samples prior to and during immunotherapy, along with clinical evaluations. Our 16S rRNA taxonomy survey on the fecal samples revealed an elevation of the Prevotella/Bacteroides ratio in patients, with a preferred response to anti–PD-1/PD-L1 treatment, and a particular subgroup of responders harboring a significantly higher abundance of Prevotella, Ruminococcaceae, and Lachnospiraceae. The shotgun metagenomes of the same samples showed that patients exhibiting different responses had differential abundance of pathways related to nucleoside and nucleotide biosynthesis, lipid biosynthesis, sugar metabolism, and fermentation to short-chain fatty acids (SCFA). Gut bacteria that were capable of SCFA production, including Eubacterium, Lactobacillus, and Streptococcus, were positively associated with anti–PD-1/PD-L1 response across different GI cancer types. We further demonstrated that the identified bacterial taxa were predictive of patient stratification in both our cohort and melanoma patients from two previously published studies. Our results thus highlight the impact of gut microbiomes on anti–PD-1/PD-L1 outcomes, at least in a subset of patients with GI cancer, and suggest the potential of the microbiome as a marker for immune-checkpoint blockade responses. See articles by Tomita et al., p. 1236, and Hakozaki et al., p. 1243

Oxidative damage is involved in many chronic diseases including those cited as the major causes of death in Western societies such as cardiovascular disorders and cancer. Antioxidants may prevent these degenerative processes by various mechanisms including the scavenging of free radicals. Intake of antioxidant supplements is associated with preventing oxidative damages. This study investigated the absorption and antioxidant effects of a xanthone-rich mangosteen liquid in healthy human volunteers after the acute consumption of 59 mL of the supplement. The liquid contained mangosteen, aloe vera, green tea, and multivitamins. Results indicated that R-mangostin and vitamins B 2 and B 5 were bioavailable, with observed C max at t max of around 1 h. The antioxidant capacity measured with the oxygen radical absorbance capacity (ORAC) assay was increased with a maximum effect of 18% after 2 h, and the increased antioxidant level lasted at least 4 h. Overall, this study demonstrated the bioavailability of antioxidants from a xanthone-rich mangosteen product and its in vivo antioxidant effects.

A simple, specific, high-throughput colorimetric method based on the reaction of 4-dimethylaminocinnamaldehyde (DMAC) with flavan-3-ols was developed to determine total procyanidins in selected cacao-based products. Extracts of defatted samples were dispensed into a 96-well plate and reacted with DMAC. The absorbance of the reaction products was measured at 640 nm and compared to commercially available procyanidin B2 as a standard. The use of the 96-well plates and a plate reader dramatically improved sample throughput. A standard protocol was established and used for further studies. The calibration was found to be linear from 1100 ppm. The DMAC reagent reacted relatively specifically to (–)-epicatechin, (+)-catechin, epigallocatechin, gallocatechin, the gallates of catechin, epicatechin, gallocatechin, and epigallocatechin, oligomeric procyanidins of cocoa up to n = 4, and A-type procyanidins. Little or no reaction occurred with cyanidins and representative compounds of phenolic acids, flavones, flavanones, flavonols, anthocyanidins, isoflavones, and stilbenes. Sample precision studies were carried out on 10 different test materials over several weeks, and yielded RSD values of 4.0 to 9.5%. The method was ring-tested in three laboratories using blinded test materials including cocoa beans, cocoa powder, chocolate liquor, dark chocolate, and milk chocolate. There was excellent agreement of the results between laboratories.

This study aimed to systematically review and identify the risk factors for the recurrence of diabetic foot ulcers (DFUs) among diabetic patients. PUBMED, EMBASE, Web of Science, Cochrane Library, China Biology Medicine (CBM), China National Knowledge Infrastructure (CNKI), WanFang, and VIP databases were electronically searched to identify eligible studies updated to January 2019 to collect case‐control studies or cohort studies on the risk factors for the recurrence of DFUs. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of included studies using the Newcastle‐Ottawa Scale. A meta‐analysis was performed using RevMan 5.3. Nine retrospective cohort studies were included, in which 1426 patients were enrolled, 542 in the DFU recurrence group and 884 in the non‐recurrent DFU group. Risk factors for the recurrence of DFUs included male gender (odds ratio [OR] = 1.38, 95% confidence interval [CI], 1.07‐1.78, P < .05), smoking (OR = 1.66, 95% CI, 1.26‐2.20, P = .0004), duration of diabetes (OR = 4.43, 95% CI, 1.96‐6.90, P = .0004), duration of past DFUs (OR = 1.02, 95% CI, 1.00‐1.03, P = .006), plantar ulcers (OR = 5.31, 95% CI, 4.93‐5.72, P <.00001), peripheral artery disease (OR = 1.65, 95% CI, 1.20‐2.28, P = .002), and diabetic peripheral neuropathy (OR = 2.15, 95% CI, 1.40‐3.30, P = .0005). No significant differences were found in age, body mass index, total cholesterol, diabetic nephropathy, diabetic retinopathy, or hypertension. Health care staff should pay attention to the identified risk factors for the recurrence of DFUs. Because of the limited quality and quantity of the included studies, rigorous studies with adequate sample sizes are needed to verify the conclusion.

The effect of a mangosteen product containing multivitamins and essential minerals was tested on immune function and well-being in healthy adults. A randomized, double blinded, placebo-controlled study was conducted in 59 healthy human subjects (40-60 years old). Changes from baseline immune function were measured after a 30-day consumption of the mangosteen product and the placebo. The subjects' self-appraisal of their health status was also surveyed. A xanthone-rich mangosteen product intake increased mean values for peripheral T-helper cell frequency (P = .020) and reduced the serum C-reactive protein concentration (P = .014). Increases in peripheral CD4/CD8 double-positive (DP) T-cell frequency and serum complement C3, C4, and interleukin (IL)-1alpha concentrations were significantly higher in the experimental group than in the placebo group (DP, P = .038; C3, P = .017; C4, P = .031; IL-1alpha, P = .006). At the end of study, serum IL-1alpha and IL-1beta concentrations in the study group were significantly higher than that in the placebo group (IL-1alpha, P = .033; IL-1beta, P = .04). Furthermore, more participants in the experimental group reported greatly improved overall health status compared with participants receiving placebo (P = .001). The results indicated that the intake of an antioxidant-rich product significantly enhanced immune responses and improved the subject's self-appraisal on his or her overall health status.