Probiotics may have the potential to protect against breast cancer, partly through systemic immunomodulatory action and active impact upon intestinal microbiota. Given a few clinical studies on their curative role, we conducted a systematic review of the potential effects of probiotics in breast cancer patients and survivors of breast cancer, aiming to support further clinical studies. A literature search was performed using PubMed, Embase, and the CENTRAL databases from inception through to March 2022. A total of eight randomized clinical trials were identified from thirteen articles published between 2004 and 2022. We evaluated quality-of-life measures, observed bacterial species and diversity indices, probiotic-related metabolites, inflammatory biomarkers, and other responses in breast cancer patients and survivors. Results were synthesized qualitatively and quantitatively using random-effects meta-analysis. Different probiotics supplements utilized included Lactobacillus species alone (Lacto), with or without estriol; probiotic combinations of Lactobacillus with Bifidobacterium (ProLB), with or without prebiotic fructooligosaccharides (FOS); ProLB plus Streptococcus and FOS (ProLBS + FOS); and ProLB plus Enterococcus (ProLBE). We found that use of ProLBS with FOS in breast cancer patients and use of ProLBE in survivors of breast cancer show potential benefits in countering obesity and dyslipidemia. ProLBS with FOS use decreases pro-inflammatory TNF-α in breast cancer survivors and improves quality of life in those with breast-cancer-associated lymphedema. Supplementing probiotics capsules (109 CFU) with a prebiotic and using an intake duration of 10 weeks could provide a better approach than probiotics alone.

IntroductionDysbiosis characterises breast cancer through direct or indirect interference in a variety of biological pathways; therefore, specific microbial patterns and diversity may be a biomarker for the diagnosis and prognosis of breast cancer. However, there is still much to determine about the complex interplay of the gut microbiome and breast cancer.ObjectiveThis study aims to evaluate microbial alteration in breast cancer patients compared with control subjects, to explore intestine microbial modification from a range of different breast cancer treatments, and to identify the impact of microbiome patterns on the same treatment-receiving breast cancer patients.MethodsA literature search was conducted using electronic databases such as PubMed, Embase, and the CENTRAL databases up to April 2021. The search was limited to adult women with breast cancer and the English language. The results were synthesised qualitatively and quantitatively using random-effects meta-analysis.ResultsA total of 33 articles from 32 studies were included in the review, representing 19 case-control, eight cohorts, and five nonrandomised intervention researches. The gut and breast bacterial species were elevated in the cases of breast tumours, a significant increase in Methylobacterium radiotolerans (p = 0.015), in compared with healthy breast tissue. Meta-analysis of different α-diversity indexes such as Shannon index (p = 0.0005), observed species (p = 0.006), and faint’s phylogenetic diversity (p < 0.00001) revealed the low intestinal microbial diversity in patients with breast cancer. The microbiota abundance pattern was identified in different sample types, detection methods, menopausal status, nationality, obesity, sleep quality, and several interventions using qualitative analysis.ConclusionsThis systematic review elucidates the complex network of the microbiome, breast cancer, and therapeutic options, with the objective of providing a link for stronger research studies and towards personalised medicine to improve their quality of life.

Background: Cannabis is being legalized in many countries for therapeutic and recreational purposes. The cannabinoid compounds are mainly involved in the host metabolism under the endocannabinoid system, and they regulate the intestinal microbiota via an immunomodulatory mechanism leading to obtaining positive effects on the gastrointestinal and immunological systems. Objective: The review is to systematically evaluate their association and the impact of the microbiome on cannabis treatment to support further clinical trials. Methods: Utilizing online sources like PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, a literature search was carried out up to July 20, 2022. The search was restricted to adults with clinical abnormalities and the use of English. An examination of predetermined subgroups under various disease conditions was carried out. The data was combined quantitatively. Result: The study comprised 9 studies with 2526 participants; two were clinical trials and the others were observational studies. One significant factor influencing microbiota variation was marijuana (MJ) usage [R2=0.01, p=0.14]. In HIV patients who used MJ, there were elevated levels of Fusobacterium and Anaerotruncus and lower concentrations of Dorea. The genus Rothia was dominant, but Capnocytophaga, Fusobacterium, and Porphyromonas were low at the tongue site, whereas high Selenomonas and low Streptococcus were detected at the oral pharynx region in MJ users in oral cancer patients. Following cannabis use, Lactobacilli and S. mutan were increased in patients with musculoskeletal discomfort. Increases in the circulation of endocannabinoids are associated with an increase in SCFA-producing bacteria and a decrease in the proinflammatory species Collinsella in patients with knee arthritis. Lower Prevotella:Bacteroides ratios were more frequently linked to higher lifetime MJ consumption in those with cognitive impairments (p=0.052). Increased PEA excretion correlated with decreased microbial diversity, which caused anhedonia/amotivation to worsen. A. muciniphila was substantially more prevalent in obese patients after OEA administration. Conclusion: Data from a systematic review suggest that cannabis usage and supplementation of medical cannabis in a variety of clinical problems had links with altering the human microbiome on gut, oral, rectal, and vaginal discharge. It must be taken into consideration in future research on the therapeutic effects of cannabis on patients.