The use of prebiotics to escalate certain gut flora is a current aspect of research for effective gut ecology. In the present study we appraise the efficacy of gum odina obtained from the bark of Odina wodier (Anacardiaceae), which is not fully degraded (16%) in the upper GI tract and becomes available to the lower region, as a prebiotic. An in vitro prebiotic activity assay established a quantitative score to describe the extent to which gum odina supports the selective growth of probiotics with a maximum of 5.60 ± 0.11 for Lactobacillus plantarum MTCC 6160. The polysaccharide, upon fermentation, also liberates lactic acid (0.46 ± 0.003 mg ml⁻¹) and acetic acid (1.03 ± 0.003 mg ml⁻¹). In vivo studies revealed that natural gum selectively stimulates Lactobacillus sp., and eliminates enteric pathogens with a C.F.U. of 384.48 ± 0.11 and 40.56 ± 0.17 respectively on the 8^th day. The changes in the level of β-galactosidase signify maturation of macrophages in the gut environment. It also boosts the immune system by increasing sIgA upon infection from the 5^th day in the gut, when incorporated into the feed of mice. Moreover an increase in levels of IFNγ on the 5^th day also manifest additional protection against various pathogen-induced primary and secondary infections. Thus, gum odina is a potential prebiotic which not only provides nutrition but also improves gut ecology.

Southeast Asia is attractive for tourism. Unfortunately, travelers to this region are at risk of becoming infected with Shigella. We conducted a meta-analysis to provide updates on Shigella prevalence in Southeast Asia, along with their serogroups and serotypes. We conducted a systematic search using PubMed, EMBASE, and Web of Science for peer-reviewed studies from 2000 to November 2022. We selected studies that detected Shigella in stools by culture or polymerase chain reaction (PCR). Two reviewers extracted the data using a standardized form and performed quality assessments using the Joanna Briggs Institute checklist. The random effects model was used to estimate the pooled prevalence of Shigella. During our search, we identified 4376 studies. 29 studies (from six Southeast Asian countries) were included in the systematic review, 21 each in the meta-analysis of the prevalence of Shigella (Sample size: 109545) and the prevalence of Shigella serogroups. The pooled prevalence of Shigella was 4% (95% CI: 4-5%) among diarrhea cases. Shigella sonnei was the most abundant serogroup in Thailand (74%) and Vietnam (57%), whereas Shigella flexneri was dominant in Indonesia (72%) and Cambodia (71%). Shigella dysenteriae and Shigella boydii were uncommon (pooled prevalence of 1% each). The pooled prevalence of Shigella was 5% (95% CI: 4-6%) in children aged <5 years. The pooled prevalence showed a decreasing trend comparing data collected between 2000-2013 (5%; 95% CI: 4-6%) and between 2014-2022 (3%; 95% CI: 2-4%). Shigella prevalence was 6% in studies that included participants with mixed pathogens versus 3% in those without. Shigella flexneri serotype 2a was the most frequently isolated (33%), followed by 3a (21%), 1b (10%), 2b (3%), and 6 (3%). This study provides compelling evidence for the development of effective Shigella vaccines for residents of endemic regions and travellers to these areas.

It is well established that prebiotics have a profound influence on colonic microbiota which in turn play an essential role in ameliorating the host’s health. This study is focused on Gum Odina (GO), a reported prebiotic in our earlier work, and its impact on colorectal cancer (CRC). GO, upon utilization by probiotics, liberates short-chain fatty acids, acetic acid (0.864 ± 0.050 mg ml⁻¹) and butyric acid (2.303 ± 0.083 mg ml⁻¹) predominantly and increases colonization of Lactobacillus sp. and Bifidobacterium sp. in a gut simulator. The in vivo preventive study of CRC was conducted on Swiss albino mice using 1,2-dimethyl hydrazine (DMH) along with inulin and GO as the standard and test prebiotic, respectively. Scanning electron micrographs of the colon depict that the severity of mucosal dysplasia, flat lesions and loss of goblet cells was quite low in the GO group compared to the DMH alone treated group. The same was noticed in the histomicrograph in terms of alteration of the colonic architecture and abnormalities in the submucosa. Administration of DMH also caused oxidative burst as the levels of reactive oxygen species and lipid peroxidation significantly increased (p < 0.05) but reduced by 29.35% and 27.65%, respectively, in the GO group. Moreover, the levels of glutathione, glutathione-S-transferase, superoxide dismutase and catalase in the colonic tissues significantly increased (p < 0.05) by 31.26%, 10.96%, 12.4% and 6.37%, respectively, when compared to IN, a standard prebiotic. Thus, GO possesses CRC-preventing along with antioxidant properties and slows the overall tumor genesis process.

High-dose radiation exposure results in gastrointestinal (GI) acute radiation syndrome identified by the destruction of mucosal layer, intestinal growth barrier dysfunction, and aberrant inflammatory responses. Further, radiation causes gut microbiome dysbiosis characterized by diminished microbial diversity, mostly commensal bacteria, and the spread of bacterial pathogens that trigger the recruitment of immune cells and the production of pro-inflammatory factors that lead to further GI tissue damage. Currently, there are no U.S. Food and Drug Administration (FDA) approved countermeasures that can treat radiation-induced GI injuries. To meet this critical need, Synedgen Inc. has developed a glycopolymer radiomitigator (MIIST305) that is specifically targeted to the GI tract, which acts by intercalating into the mucus layer and the glycocalyx of intestinal epithelial cells that could potentially ameliorate the deleterious effects of radiation. Male C57BL/6J adult mice were exposed to 13 Gy partial body X-irradiation with 5% bone marrow shielding and MIIST305 was administered on days 1, 3, and 5 post-irradiation. Approximately 85% of the animals survived the irradiation exposure and were apparently healthy until the end of the 30-day study period. In contrast, no control, Vehicle-treated animals survived past day 10 at this radiation dose. We show that MIIST305 improved intestinal epithelial barrier function and suppressed systemic inflammatory responses mediated by radiation-induced pro-inflammatory cytokines. Taxonomic profiling and community structure of the fecal and colonic mucosa microbiota demonstrated that MIIST305 treatment increased microbial diversity and restored abundance of beneficial commensal bacteria, including Lactobacillus and Bifidobacterium genera while suppressing potentially pathogenic bacteria Enterococcus and Staphylococcus compared with Vehicle-treated animals. In summary, MIIST305 is a novel GI-targeted therapeutic that greatly enhances survival in mice exposed to lethal radiation and protects the GI tract from injury by restoring a balanced gut microbiota and reducing pro-inflammatory responses. Further development of this drug as an FDA-approved medical countermeasure is of critical importance.

High-dose radiation exposure results in gastrointestinal (GI) acute radiation syndrome identified by the destruction of mucosal layer, intestinal epithelial barrier dysfunction, and aberrant inflammatory responses. In addition, radiation causes gut microbiome dysbiosis characterized by diminished microbial diversity, reduction in the abundance of beneficial commensal bacteria, and the spread of bacterial pathogens that trigger the recruitment of immune cells and the production of pro-inflammatory factors that lead to further GI tissue damage. Currently, there are no FDA- approved countermeasures that can treat radiation-induced GI injury. To meet this critical need, Synedgen Inc ., has developed a glycopolymer radiomitigator (MIIST305) that is specifically targeted to the GI tract which acts by intercalating into the mucus layer and the glycocalyx of intestinal epithelial cells that could potentially ameliorate the deleterious effects of radiation. Male C57BL/6J adult mice were exposed to 13 Gy total body X-irradiation with 5% bone marrow shielding and MIIST305 was administered on days 1, 3, and 5 post-irradiation. Approximately 85% of the animals survived the irradiation exposure and were apparently healthy until the end of the 30-day study period. In contrast, no control, vehicle-treated animals survived past day 10 at this radiation dose. We show that MIIST305 improved intestinal epithelial barrier function and suppressed systemic inflammatory response mediated by radiation-induced pro-inflammatory cytokines. Taxonomic profiling and community structure of the fecal and colonic mucosa microbiota demonstrated that MIIST305 treatment increased microbial diversity and restored abundance of beneficial commensal bacteria, including Lactobacillus and Bifidobacterium genera, while suppressing potentially pathogenic bacteria compared with vehicle-treated animals. In summary, MIIST305 is a novel GI-targeted therapeutic that greatly enhances survival in mice exposed to lethal radiation and protects the GI tract from injury by restoring a balanced gut microbiota and effectively reducing proinflammatory responses. Further development of this drug as an FDA-approved medical countermeasure will be of critical importance in the event of a radiation public health emergency.

Maintaining gut-microbiome homeostasis is the biggest issue worldwide as per public health concerns. Gut probiotics not only inhibit pathogen invasion in the systemic circulation but also help us metabolize complex food. Therefore, for decades, gut dysbiosis has been proven to be the gateway to several diseases, leading to comorbidity and even mortality. Prebiotics are natural products, mainly nondigestible food ingredients, that help the selective growth of probiotic bacteria in the gut. This study focuses on the novel Gum-Odina (GO) prebiotic and its efficacy on gut microbial metabolite modulation and maintaining gut barrier integrity. Gut wall enterocytes are integrated by a series of tight junctional (TJ) proteins. This study explains the effect of GO prebiotic-modulated gut metabolites on tight-junctional (TJ) protein expression in a murine colon Organoid model. Fecal microbiota from a colitis patient were used to inoculate the SHIME gut simulator, comprising a colitis control run and a Gum-Odina-supplemented run to enrich commensal bacteria selectively. Metabolites from both groups were then applied to healthy colon organoids. According to the mRNA expression analysis, tight junctional sealing proteins such as Zonula occludens, or ZO-1, Occludin, Claudin-1, 4, and 5 were significantly upregulated in the colon organoids upon Gum-Odina administration, whereas no change in the Junctional Adhesion Molecule-A or JAM-A was observed. Downregulation of sealing TJ proteins is the Hallmark of Leaky gut, which was successfully reversed using the Gum-Odina supplement. Hence, Gum-Odina prebiotics have a promising capability to reduce colitis-induced gut permeability and can be considered to be a therapeutic agent in the future.