Colorectal cancer (CRC) is the World’s third most frequently diagnosed cancer type. It accounted for about 9.4% mortality out of the total incidences of cancer in the year 2020. According to estimated facts by World Health Organization (WHO), by 2030, 27 million new CRC cases, 17 million deaths, and around 75 million people living with the disease will appear. The facts and evidence that establish a link between the intestinal microflora and the occurrence of CRC are quite intuitive. Current shortcomings of chemo- and radiotherapies and the unavailability of appropriate treatment strategies for CRC are becoming the driving force to search for an alternative approach for the prevention, therapy, and management of CRC. Probiotics have been used for a long time due to their beneficial health effects, and now, it has become a popular candidate for the preventive and therapeutic treatment of CRC. The probiotics adopt different strategies such as the improvement of the intestinal barrier function, balancing of natural gut microflora, secretion of anticancer compounds, and degradation of carcinogenic compounds, which are useful in the prophylactic treatment of CRC. The pro-apoptotic ability of probiotics against cancerous cells makes them a potential therapeutic candidate against cancer diseases. Moreover, the immunomodulatory properties of probiotics have created interest among researchers to explore the therapeutic strategy by activating the immune system against cancerous cells. The present review discusses in detail different strategies and mechanisms of probiotics towards the prevention and treatment of CRC.

The outbreak of 2019 novel corona virus disease (COVID-19) is now a global public health crisis and declared as a pandemic. Several recent studies suggest that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein binds to human angiotensin-converting enzyme 2 (ACE2). The information obtained from these structural and biochemical studies provides a strong rationale to target SARS-CoV-2 spike protein and ACE2 interaction for developing therapeutics against this viral infection. Here, we propose to discuss the scope of bioengineered probiotics expressing human ACE2 as a novel therapeutic to control the viral outbreak.

Characterization of new potential probiotics is desirable in the eld of research of probiotics for their extensive use in health and disease. Tribes could be unusual source of probiotics due to their unique food habits and least dependence on medications and consumption of antibiotics. The aim of the present study is to isolate lactic acid bacteria from tribal fecal samples of Odisha, India, and characterize their genetic and probiotic attributes. In this context one of the catalase-negative and Gram-positive isolates, identi ed using 16S rRNA sequencing as Lactobacillus salivarius,was characterized in vitro for its acid and bile tolerance, cell adhesion and antimicrobial properties. The whole genome sequence was obtained and analyzed for strain level identi cation, presence of genomic determinants for probiotic-speci c features, and safety. Genes responsible for its antimicrobial and immunomodulatory functions were detected. The secreted metabolites were analyzed using high resolution mass spectroscopy; the results indicated that the antimicrobial potential could be due to the presence of pyroglutamic acid, propionic acid, lactic acid, 2-hydroxyisocaproic acid, homoserine, and glutathione, and the immuno-modulating activity, contributed by the presence of short chain fatty acids such as acetate, propionate, and butyrate. So, to conclude we have successfully characterized a Ligilactobacillus salivarius species with potential antimicrobial and immunomodulatory ability. The health-promoting effects of this probiotic strain and/or its derivatives will be investigated in future.JD and MS were involved in the conception and design of the study, conducting in vitro characterization studies, acquisition of data, data analysis, sample preparation for WGS and bioinformatics analysis, preparation of the initial draft and further revision. SD contributed to the bioinformatics analysis of the WGS data, preparation of the initial draft, and further revision. APM, SM, and PP coordinated sample collection from the tribal people. SKD assisted in in vitro characterization of the isolates. SK was involved in both in vitro characterization studies and initial draft preparation as well. BP assisted in analysis of the biochemical composition of the CFS sample using HRMS. SS contributed to the conception, design, and overall supervision of the study with critical review and proofreading of the article. All the authors have read, reviewed, and nally approved the manuscript.

Significance and Impact of the Study: This is the first attempt to check the prevalence of different ARGs in the gut microbiota of tribal people of Nabarangpur, Odisha, which is a small contributing step in controlling the evolving antibiotic resistance in India. The results of this study showed the dominance of tetracycline resistance genes (tetW, tetQ and tetM) as well as the similar pattern of distribution of ARGs among the three major tribes of this location. These findings provide a reference to monitor the evolution of antimicrobial resistome in this population in the future.

Pancreatic cancer is still one of the malignancies with a very poor prognosis worldwide. In the recent past, the gut microbiota has been shown to have a role in pancreatic cancer patients’ survival and response to the therapy. Out of the possible mechanisms, the role of gut microbiota in shaping the microbial composition of pancreatic tumor and its effect on intra-tumor immune modulation has emerged as a potential therapeutic strategy. Modulation of gut microbiota for targeting pancreatic cancer initiation, progression and therapy could be achieved through different processes like treatment through faecal microbiota transplantation (FMT), antibiotics, prebiotics, probiotics, and synbiotics. In the recent past, various clinical and experimental pieces of evidence have demonstrated the efficacy of probiotics in cancer prevention, treatment and management. In this chapter, efforts have been directed towards summarizing the prospects and challenges associated with the use of probiotics and probiotics-derived products against pancreatic cancer.