The human intestine hosts diverse microbial communities that play a significant role in maintaining gut-skin homeostasis. When the relationship between gut microbiome and the immune system is impaired, subsequent effects can be triggered on the skin, potentially promoting the development of skin diseases. The mechanisms through which the gut microbiome affects skin health are still unclear. Enhancing our understanding on the connection between skin and gut microbiome is needed to find novel ways to treat human skin disorders. In this review, we systematically evaluate current data regarding microbial ecology of healthy skin and gut, diet, pre- and probiotics, and antibiotics, on gut microbiome and their effects on skin health. We discuss potential mechanisms of the gut-skin axis and the link between the gut and skin-associated diseases, such as psoriasis, atopic dermatitis, acne vulgaris, rosacea, alopecia areata, and hidradenitis suppurativa. This review will increase our understanding of the impacts of gut microbiome on skin conditions to aid in finding new medications for skin-associated diseases.

Plants contain a variety of bioactive compounds that provide them antimicrobial properties, which can be used to develop novel antibiotics. The current research evaluated the antibacterial activity of 6 medicinal plants Sphagneticola calendulacea (Chinese wedelia), Enydra fluctuans (Buffalo spinach), Chenopodium album (Goosefoot), Mentha arvensis (Wild mint), Mimosa diplotricha (Nila grass), and Averrhoa bilimbi (Cucumber tree) against Urinary Tract Infection (UTI)- causing pathogens (Staphylococcus spp., Proteus spp., Pseudmonas spp., Escherichia coli and Enterobacter spp.). The bacterial contamination of these plants was evaluated by using their surface-washed water. The combined effects of commercially available antibiotics along with these medicinal plants were also tested. We used the solvent extraction method, conventional cell culture technique, minimum inhibitory concentration (MIC) assay, and disc diffusion method for our analysis. The surface-washed water was contaminated with variable bacteria. The plants displayed notable antibacterial activity against most of the tested bacteria. Ethanol and hot water extract of plants exhibited minimum inhibitory effects, while the methanol extract of plants showed very potent antibacterial activity against most of the bacteria with inhibitory zone diameter up to 14 mm. In the case of combined effects, the zone diameter increased up to 26 mm, which is a significant improvement compared to the individual plant extracts. This data suggested that the combination of two antibacterial agents, one natural and the other synthetic, would be more efficient in the treatment of multidrug-resistant bacteria than a single monotherapy of either of the antibacterial agents.

Probiotics are put forward as food to ensure the maintenance of the equilibrium of the intestinal flora. Prolonged usage of probiotics in food ingredients for human as well as in animal feed has not exposed any side effects yet. Present study attempted to justify the effects of some commercially available probiotics (Good-gut, Lubenna, Probio and Protein restro) and commonly used antibiotics (Streptomycin, Gentamycin, Ampicillin, Methicillin, Azithromycin, Erythromycin, Ceftrizone, Imepenem, Ciprofloxacin and Tetracycline) on the bacteria which were previously isolated from food samples. The anti-bacterial potential of the probiotics was aimed to be checked through the agar well diffusion method and the antibiogram of the synthetic drugs was determined by disc-diffusion method (Kirby Bauer technique). The minimum inhibitory concentration (MIC) of the probiotics were examined through broth micro dilution assay. Almost all the probiotic samples exhibited antibacterial activity against the tested bacteria within the range of 10 mm–30 mm except Bacillus spp. and Salmonella spp. The lowest MIC values 3 mg/ml was determined with Luvena for Pseudomonas spp. and Shigella spp. while the maximum MIC 20 mg/ml was recorded for Good gut and Probio against Salmonella spp. and E. coli. Meanwhile, majority of the tested pathogens were detected to be resistant against more than one antibiotic as MDR strains except gentamycin, streptomycin and azithromycin. During the combination method, the zone diameter increased remarkably with a clear indication of synergistic effects compared to their individual activity. This study substantiated that the deployment of a combination of two antibacterial medications in order to combat the multi-drug resistant bacteria would rather be efficacious than the application of either antimicrobial agent alone.

Along with the raw fishes, dry fishes also have a huge contribution to meet up the demand of protein in our daily meal. The assay of microbiological quality is therefore needed to ensure the public health safety. The present study was emphasized on the existence of pathogenic bacteria in raw and dry fish. A total of 50 samples of raw fishes and sun-dried fishes was accumulated aseptically for microbiological quality analysis. Isolation of bacteria was done by spread plate method. All the samples including both (raw and dry) fishes harbored bacteria and fungi up to 106 CFU/g. E. coli was found in all samples as a specific pathogen. In case of raw fishes total viable count (TVC) and total coliform count (E. coli) were recorded up to 2.5x106 CFU/g and 5.2 x104 CFU/g respectively whereas a significant load of Salmonella spp. was observed in almost all samples. Staphylococcus spp. and Pseudomonas spp. were present up to 5 x102 CFU/g and 1.8 x 102 CFU/g respectively. Likewise, total viable count (TVC), total coliform count (E. coli) and fungal load were recorded in dry fish up 3.50 x 105 CFU/g, 1.2 x103 CFU/g respectively. Fungal growth was observed in all experimental raw and dried fishes. For most of the pathogenic isolates, higher rates of resistance were found against Ceftriaxone, Penicillin, Nalidixic acid, Neomycin. On the other hand, most of the isolates were found to retain higher sensitivity against Imipenem, Ciprofloxacin, Tetracyclin and Amoxicillin. This data suggested that the dry fish harbored fewer bacteria than raw fish and sun drying method is still a useful technique for the preservation of fish.

Present study attempted to assess the level of microbiological contamination in oral herbal medicines, frequently used for medications, through conventional cultural and biochemical tests along with the antibiogram of the isolates. Moreover, the anti-bacterial potential of the herbal medicines was also aimed to be checked by the agar well diffusion method and minimum inhibitory concentration (MIC) assay. Out of 10 categories of liquid oral herbal medicine samples (n = 50) studied, all were found to be contaminated with bacteria (10³-10⁵ cfu/mL), specifically with Staphylococcus spp. in 8 samples; while 2 samples harbored Klebsiella spp. Fungal presence was observed only in one sample. Study of antibiogram revealed Klebsiella spp. to be strongly resistant against penicillin G and erythromycin, whereas S. aureus possessed 80% sensitivity. The in vitro anti-bacterial activity was observed in 7 samples. Of them, one sample was found to exhibit the activity against almost all the test bacteria and another was found effective against 5 out of 8 test bacteria. Five samples showed the activity within a minor range while 3 samples were devoid of such trait. Samples 2 and 4 were found to stall the bacterial growth below 10 mg/mL of concentration in MIC test. Overall, the prevalence of specific pathogens was not so significant in the samples studied as well as only one drug-resistant isolate was identified. Besides, the anti-bacterial trait of 5 samples indicated that most of herbal medicines might be considered effective for medication.

The ability of many bacteria to adhere on the host surfaces and forming biofilms has major implications in a wide variety of industries including the food industry, where biofilms may create a persistent source of contamination. In the same environmental condition, the multiple bacterial species can closely interact with each other and may easily enhance their drug resistance capability, which finally increases the multi-drug resistant (MDR) attribute of the species. The present study examined whether the mixed-species biofilm possesses any impact on the enhancement of the antibiotic resistance of the planktonic or single-cell bacterial isolates present in the fish samples. In this regard, Cyprinus rubrofuscus (Koi), Heteropneustes fossilis (Shing) and Mystus vittatus (Tengra) fishes were collected and subjected to form an in vitro biofilm by shaking condition into the wise bath. The drug-resistant pattern was determined by the Kirby Bauer technique. All the samples exhibited a huge array (up to 10⁷ cfu/ml or g) of bacteria such as E. coli, Klebsiella spp., Vibrio spp., Salmonella spp., Proteus spp. and Staphylococcus spp. The isolates from both the bulk samples and their corresponding biofilms were subjected to antibiogram assay using antibiotics such as Ampicillin (10 µg), Erythromycin (15 μg), Streptomycin (STP 10 μg), Oxacillin (10 µg), Nalidixic acid (30 µg). Before biofilm formation, few of the isolates were found to be sensitive and few were resistant against the antibiotics. But when the species were isolated from the biofilm the sensitive one acquired drug resistance and resistant strain unveiled more resistance towards the same antibiotics. The present study revealed extensive bacterial contamination in fish samples among those some were resistant against the supplied drugs. After the formation of multi-species biofilm, the isolates became more resistant against the same drugs that is alarming for consumers and major obstacles to maintain sustainable health.