Changes in present-day society such as diets with more sugar, salt, and saturated fat, bad habits and unhealthy lifestyles contribute to the likelihood of the involvement of the microbiota in inflammatory diseases, which contribute to global epidemics of obesity, depression, and mental health concerns. The microbiota is presently one of the hottest areas of scientific and medical research, and exerts a marked influence on the host during homeostasis and disease. Fermented foods and beverages are generally defined as products made by microbial organisms and enzymatic conversions of major and minor food components. Further to the commonly-recognized effects of nutrition on the digestive health (e.g., dysbiosis) and well-being, there is now strong evidence for the impact of fermented foods and beverages (e.g., yoghurt, pickles, bread, kefir, beers, wines, mead), produced or preserved by the action of microorganisms, on general health, namely their significance on the gut microbiota balance and brain functionality. Fermented products require microorganisms, i.e., Saccharomyces yeasts and lactic acid bacteria, yielding alcohol and lactic acid. Ingestion of vibrant probiotics, especially those contained in fermented foods, is found to cause significant positive improvements in balancing intestinal permeability and barrier function. Our guts control and deal with every aspect of our health. How we digest our food and even the food sensitivities we have is linked with our mood, behavior, energy, weight, food cravings, hormone balance, immunity, and overall wellness. We highlight some impacts in this domain and debate calls for the convergence of interdisciplinary research fields from the United Nations’ initiative. Worldwide human and animal medicine are practiced separately; veterinary science and animal health are generally neither considered nor inserted within national or international Health discussions. The absence of a clear definition and subsequent vision for the future of One Health may act as a barrier to transdisciplinary collaboration. The point of this mini review is to highlight the role of fermented foods and beverages on gut microbiota and debate if the need for confluence of transdisciplinary fields of One Health is feasible and achievable, since they are managed by separate sectors with limited communication.

Hydrolysis of the plant cell wall polysaccharides cellulose and xylan requires the synergistic interaction of a repertoire of extracellular enzymes. Recently, evidence has emerged that anaerobic bacteria can synthesize high levels of periplasmic xylanases which may be involved in the hydrolysis of small xylooligosaccharides absorbed by the micro-organism. Cellvibrio mixtus, a saprophytic aerobic soil bacterium that is highly active against plant cell wall polysaccharides, was shown to express internal xylanase activity when cultured on media containing xylan or glucose as sole carbon source. A genomic library of C. mixtus DNA, constructed in λZAPII, was screened for xylanase activity. The nucleotide sequence of the genomic insert from a xylanase-positive clone that expressed intracellular xylanase activity in Escherichia coli revealed an ORF of 1137 bp (xynC), encoding a polypeptide with a deduced M r of 43 413, defined as xylanase C (XylC). Probing a gene library of Pseudomonas fluorescens subsp. cellulosa with C. mixtus xynC identified a xynC homologue (designated xynG) encoding XylG ; XylG and xynG were 67 % and 63 % identical to the corresponding C. mixtus sequences, respectively. Both XylC and XylG exhibit extensive sequence identity with family 10 xylanases, particularly with non-modular enzymes, and gene deletion studies on xynC supported the suggestion that they are single-domain xylanases. Purified recombinant XylC had an M r of 41 000, and displayed biochemical properties typical of family 10 polysaccharidases. However, unlike previously characterized xylanases, XylC was particularly sensitive to proteolytic inactivation by pancreatic proteinases and was thermolabile. C. mixtus was grown to late-exponential phase in the presence of glucose or xylan and the cytoplasmic, periplasmic and cell envelope fractions were probed with anti-XylC antibodies. The results showed that XylC was absent from the culture media but was predominantly present in the periplasm of C. mixtus cells grown on glucose, xylan, CM-cellulose or Avicel. These data suggest that C. mixtus can express non-modular internal xylanases whose potential roles in the hydrolysis of plant cell wall components are discussed.

This review examines different nutritional guidelines, some case studies, and provides insights and discrepancies, in the regulatory framework of Food Safety Management of some of the world’s economies. There are thousands of fermented foods and beverages, although the intention was not to review them but check their traditional and cultural value, and if they are still lacking to be classed as a category on different national food guides. For understanding the inconsistencies in claims of concerning fermented foods among various regulatory systems, each legal system should be considered unique. Fermented foods and beverages have long been a part of the human diet, and with further supplementation of probiotic microbes, in some cases, they offer nutritional and health attributes worthy of recommendation of regular consumption. Despite the impact of fermented foods and beverages on gastro-intestinal wellbeing and diseases, their many health benefits or recommended consumption has not been widely translated to global inclusion in world food guidelines. In general, the approach of the legal systems is broadly consistent and their structures may be presented under different formats. African traditional fermented products are briefly mentioned enhancing some recorded adverse effects. Knowing the general benefits of traditional and supplemented fermented foods, they should be a daily item on most national food guides.

Dietary changes have accompanied the evolution of humanity and is proven to be fundamental in human evolution and well-being. Nutrition is essential for survival and as a matter of health and equilibrium of the human body. About 1/3 of the human diet is composed by fermented foods and beverages, which are widely distributed and consumed in different societies around the world, no matter the culture and lifestyle. Fermented foods are derived from the fermentation process of different substrates by microorganisms, and more importantly to humans, by those with beneficial characteristics, due to the positive impact on health. Food is transformed in the gut, gaining new proprieties, and increasing its value to the organism. The effects of fermented foods and beverages can be assessed by its influence at the gut microbiota level. Recent studies show the major importance of the gut microbiota role in modulating the organism homeostasis and homeorhesis. More crosslinks between health, gut microbiota and diet are being established especially in the gut–brain axis field. Therefore, the benefits of diet, in particularly of fermented foods and beverages, should be studied and pursued in order to promote a good health status.

The microbioma is presently one of the hottest areas of scientific and medical research and exerts a marked influence on the host during homeostasis and disease. Fermented foods arise in the human relationship to the microbial environment. Further to the traditionally recognized effects of fermented foods and beverages on the digestive health and well-being there is now strong evidence on their general health benefits, namely the significance on the gut microbiota and brain functionality. We highlight the possibilities in this field, how little is still known, and call for a convergence of interdisciplinary research fields of One Health microbe-nutrition with fermented foods and gut-brain research. A consequence of civilisation, changes in present-day society in diets with more sugar, fat and salt, habits and lifestyle, contributes to the likelihood of an inflammatory microbiome, particularly the global epidemics of obesity and mental health. Although two recent papers claim that probiotics perturb rather than aid in microbiota recovery back to baseline after antibiotic administration in humans, consuming fermented foods has shown to reduce inflammation so improve gut health and the proper function of the body’s immune system.

Cellulose-binding domains (CBD) play a pivotal role during plant cell wall hydrolysis by cellulases and xylanases from aerobic soil bacteria. Recently we have reported the molecular characterisation of a single-domain endoglucanase from Cellvibrio mixtus, suggesting that some cellulases produced by this aerobic bacterium preferentially hydrolyse soluble cellulosic substrates. Here we describe the complete nucleotide sequence of a second cellulase gene, celB, from the soil bacterium C. mixtus. It revealed an open reading frame of 1863 bp that encoded a polypeptide, defined as cellulase B (CelB) with a predicted Mr of 66 039. CelB contained a glycosyl hydrolase family 5 catalytic domain at its N terminus followed by two repeated domains, which exhibited sequence identity with type VI CBD previously found in xylanases. Full-length CelB bound to cellulose while catalytically active truncated cellulase derivatives were unable to bind the polysaccharide, confirming that CelB is a modular enzyme and that the type VI CBD homologues were functional. Analysis of the biochemical properties of CelB revealed that the enzyme hydrolyses a range of cellulosic substrates, although it was unable to depolymerise Avicel. We propose that type VI CBD, usually found in xylanases, provide an additional mechanism by which cellulases can accumulate on the surface of the plant cell wall, although they do not potentiate cellulase activity directly. The results demonstrate that C. mixtus, in common with other aerobic bacteria, is able to produce cellulases that are directed to the hydrolysis of cellulose in its natural environment, the plant cell wall.

Brain cognitive reserve refers to the ability of the brain to manage different challenges that arise throughout life, making it resilient to neuropathology. Hippocampal adult neurogenesis has been considered to be a relevant contributor for brain cognitive reserve and brain plasticity. Coriolus versicolor (CV), a common healthful mushroom, has been receiving increasing attention by its antitumoral, anti-inflammatory, antioxidant, antibacterial, and immunomodulatory properties, including in the hippocampus. Herein, we evaluated whether CV biomass oral administration for 2.5 months enhances hippocampal neurogenic reserve under normal/physiological conditions, by quantifying hippocampal dentate gyrus (DG) granular cell layer (GCL) and subgranular zone (SGZ) volumes, proliferation, number and dendritic complexity features of hippocampal newly-generated neurons. We also analyzed β-catenin levels in DG newly-generated immature neurons, because it plays a major role in neurogenesis. Although no differences were observed in the volume of GCL and SGZ layers, in proliferation and in the number of newly-generated neurons of controls and CV-administered mice, we found that CV administration promotes a significant increase in dendritic length and branching and total dendritic volume of immature neurons, suggesting a positive effect of oral CV administration in the hippocampal neurogenic reserve. We also observed that β-catenin levels are increased both in the nucleus and cytoplasm of DG immature neurons, suggesting that Wnt/β-catenin signalling may play an important role in the CV positive effect on the differentiation of these cells. These data unveil a so far unexplored neurogenic potential of CV supplementation, which emerges as a possible preventive strategy for different neurological conditions.

The widespread presence of cellulose-binding domains in cellulases from aerobic bacteria and fungi suggests the existence of a strong selective pressure for the retention of these non-catalytic modules. The complete nucleotide sequence of the cellulase gene, celA, from the aerobic soil bacterium Cellvibrio mixtus, was determined. It revealed an open reading frame of 1089 bp that encoded a polypeptide, defined as cellulase A (CelA), of M(r) 41,548. CelA displayed features characteristic of an endo-beta-1,4-glucanase, rapidly decreasing the viscosity of the substrate while releasing only moderate amounts of reducing sugar. Deletion studies in celA revealed that removal of 78 nucleotides from the 5' end or 75 from the 3' end of the gene led to the complete loss of cellulase activity of the encoded polypeptides. The deduced primary structure of CelA revealed an N-terminal signal peptide followed by a region that exhibited significant identity with the catalytic domains of cellulases belonging to glycosyl hydrolase family 5. These data suggest that CelA is a single-domain endoglucanase with no distinct non-catalytic cellulose-binding domain. Analysis of the biochemical properties of CelA revealed that the enzyme hydrolyses a range of soluble cellulosic substrates, but was inactive against Avicel, xylan or any other hemicellulose. CelA was resistant to proteolytic inactivation by pancreatic proteinases and surprisingly, in view of its mesophylic origin, was shown to be thermostable. The significance of these findings in relation to the role of single-domain cellulases in plant cell wall hydrolysis by aerobic microorganisms is discussed.