Pathogen exclusion properties of canine probiotics are influenced by the growth media and physical treatments simulating industrial processes

Unlocking the power of postbiotics: A revolutionary approach to nutrition for humans and animals

Postbiotics, which comprise inanimate microorganisms or their constituents, have recently gained significant attention for their potential health benefits. Extensive research on postbiotics has uncovered many beneficial effects on hosts, including antioxidant activity, immunomodulatory effects, gut microbiota modulation, and enhancement of epithelial barrier function. Although these features resemble those of probiotics, the stability and safety of postbiotics make them an appealing alternative. In this review, we provide a comprehensive summary of the latest research on postbiotics, emphasizing their positive impacts on both human and animal health. As our understanding of the influence of postbiotics on living organisms continues to grow, their application in clinical and nutritional settings, as well as animal husbandry, is expected to expand. Moreover, by substituting postbiotics for antibiotics, we can promote health and productivity while minimizing adverse effects. This alternative approach holds immense potential for improving health outcomes and revolutionizing the food and animal products industries.

Characterization of feline-originated probiotics Lactobacillus rhamnosus CACC612 and Bifidobacterium animalis subsp. lactis CACC789 and and evaluation of their host response

BACKGROUND

Probiotics are beneficial for animal health and new potential probiotics need to be characterized for their prospective use in improving animal health. In this study, 32 bacterial strains were isolated from a Norwegian forest cat (castrated, 12 years old) and a Persian cat (castrated, 10 years old), which were privately owned and had indoor access.

RESULTS

Lactobacillus rhamnosus CACC612 (CACC612) and Bifidobacterium animalis subsp. lactis CACC789 (CACC789) were selected as potential probiotics; characterization of the two strains showed equivalent acid tolerance, similar cell adhesion rates on the HT-29 monolayer cell line, and superior bile tolerance compared to Lactobacillus rhamnosus GG (LGG). Subsequently, they exhibited inhibitory effects against a broad spectrum of pathogenic bacteria, including E. coli (KCTC 2617), Salmonella Derby (NCCP 12,238), Salmonella Enteritidis (NCCP 14,546), Salmonella Typhimurium (NCCP 10,328), Clostridium difficile JCM 1296T. From evaluating host effects, the viability of the feline macrophage cell line (Fcwf-4) increased with the treatment of CACC612 or CACC789 (P < 0.05). The induced expression of immune-related genes such as IFN-γ, IL1β, IL2, IL4, and TNF-α by immune stimulation was significantly attenuated by the treatment of CACC612 or CACC789 (P < 0.05). When 52 clinical factors of sera from 21 healthy cats were analyzed using partial least squares discriminant analysis (PLS-DA), the animals were obviously clustered before and after feeding with CACC612 or CACC789. In addition, hemoglobin and mean corpuscular hemoglobin concentration (MCHC) significantly increased after CACC612 feeding (P < 0.05).

CONCLUSIONS

In this study, feline-originated probiotics were newly characterized and their potentially probiotic effects were evaluated. These results contribute to our understanding of the functional effects of feline-derived probiotics and support their industrial applications.

Probiotic, Paraprobiotic, and Hydrolyzed Yeast Mixture Supplementation Has Comparable Effects to Zinc Oxide in Improving Growth Performance and Ameliorating Post-weaning Diarrhea in Weaned Piglets

A total of 150 21-day-old weaned piglets [(Yorkshire × Landrace) × Duroc] were randomly assigned to 3 groups (CON, TRT1, TRT2) to evaluate the effects of dietary supplementation of probiotic, paraprobiotic, and hydrolyzed yeast mixture (PPY) on growth performance, nutrient digestibility, fecal bacterial counts, fecal calprotectin contents, and diarrhea rate in a 42-day experiment (phase 1: days 1-14; phase 2: days 15-42). There were 10 replicate pens per treatment with 5 pigs per pen (three gilts and two barrows). Pigs in CON were only provided with a basal diet. Pigs in TRT1 were provided with a basal diet + 3000 mg/kg zinc oxide during phase 1 and a basal diet during phase 2. Pigs in TRT2 were provided with a basal diet + 200 mg/kg probiotic (Saccharomyces cerevisiae boulardii) + 800 mg/kg paraprobiotic (inactivated yeast strains of Saccharomyces cerevisiae and Cyberlindnera jadinii) + 10 g/kg hydrolyzed yeast mixture during phase 1, and a basal diet + 100 mg/kg probiotic + 400 mg/kg paraprobiotic mixture during phase 2. Pigs in TRT1 and TRT2 were significantly heavier at day 14 and 42 than CON pigs. Growth rate during days 1-14, 15-42, and 1-42 and feed efficiency during days 1-14 were similarly affected by treatment while feed efficiency was significantly higher for TRT2 pigs between 15-42 and 1-42 days. Moreover, nitrogen and energy digestibility in both TRT1 and TRT2 were higher than that in CON. During experimental periods, diarrhea rate in TRT1 and TRT2 was lower than that in CON. Therefore, we demonstrated that PPY supplementation had comparable effects as ZnO in improving growth performance and nutrient digestibility as well as ameliorating post-weaning diarrhea in weaned piglets.

The Effect of Lactobacillus plantarum on the Fecal Microbiota, Short Chain Fatty Acids, Odorous Substances, and Blood Biochemical Indices of Cats

Lactobacilli have played an important role in the gut health of pets. The aim of this research was to study the effects of isolated Lactobacilli (named L11) on the immune, nutrient metabolism, and gut health of cats. Twelve healthy adult cats were randomly assigned into two groups, the control group (CONTROL, n = 6, without any probiotics product) and the treatment group (probiotics, n = 6, L11 109 CFU/kg feed), while using the same dry diet. On day 28, blood and fecal samples were collected, and the blood biochemical indices, fecal microbiota, short-chain fatty acids (SCFAs), immunological parameters, and odorous substances were separately tested. The triglyceride of the blood was decreased after using L11 (p < 0.05), which could probably alleviate the occurrence of cat obesity to some extent. The sIgA of the feces was increased by 30.1% (p < 0.05), which could enhance the cat's immunity. The abundance of Bifidobacteria was increased after using L11 (p < 0.05), and the indole and 3-methylindole of the feces were both reduced compared with the control group; 3-methylindole was especially reduced by 67.3% (p < 0.05), which showed that L11 could also improve the intestinal state of cats. Therefore, this research shows that L11 could be a good choice to improve the gut health and immune functions of cats, and it is probably related to the lipid mechanism of cats.

Paraprobiotic Lacticaseibacillus rhamnosus Protects Intestinal Damage in an Experimental Murine Model of Mucositis

Intestinal mucositis (IM) is a common side effect resulting from cancer treatment. However, the management so far has not been very effective. In the last years, the role of the gut microbiota in the development and severity of mucositis has been studied. Therefore, the use of probiotics and paraprobiotics could have a potential therapeutic effect on IM. The aim of our study was to investigate the impact of the administration of Lacticaseibacillus rhamnosus (L. rhamnosus) CGMCC1.3724 and the paraprobiotic on IM in mice. For 13 days, male Balb/c mice were divided into six groups: control (CTL) and mucositis (MUC)/0.1 mL of saline; CTL LrV and MUC LrV/0.1 mL of 10⁸ CFU of viable Lr; CTL LrI and MUC LrI/0.1 mL of 10⁸ CFU of inactivated Lr. On the 10th day, mice from the MUC, MUC LrV, and MUC LrI groups received an intraperitoneal injection (300 mg/kg) of 5-fluorouracil to induce mucositis. The results showed that the administration of the chemotherapeutic agent increased the weight loss and intestinal permeability of the animals in the MUC and MUC LrV groups. However, administration of paraprobiotic reduced weight loss and maintained PI at physiological levels. The paraprobiotic also preserved the villi and intestinal crypts, reduced the inflammatory infiltrate, and increased the mucus secretion, Muc2 gene expression, and Treg cells frequency.

Beyond probiotics: a narrative review on an era of revolution

Whether knowingly or unknowingly, humans have been consuming probiotic microorganisms through traditionally fermented foods for generations. Bacteria, like lactic acid bacteria, are generally thought to be harmless and produce many metabolites that are beneficial for human health. Probiotics offer a wide range of health benefits; however, their therapeutic usage is limited because they are living organisms. As a result, the focus on the health advantages of microbes has recently shifted from viable live probiotics to non-viable microbes made from probiotics. These newly emerging non-viable microbes include paraprobiotics, postbiotics, psychobiotics, nutribiotics, and gerobiotics. Their metabolites can boost physiological health and reveal the therapeutic effects of probiotics. This new terminology in microbes, their traits, and their applications are summarized in the present review.

Effects of Postbiotics and Paraprobiotics as Replacements for Antibiotics on Growth Performance, Carcass Characteristics, Small Intestine Histomorphology, Immune Status and Hepatic Growth Gene Expression in Broiler Chickens

Background: This experiment was designed to investigate how replacing antibiotics with postbiotics and paraprobiotics could affect growth performance, small intestine morphology, immune status, and hepatic growth gene expression in broiler chickens. Methods: The experiment followed a completely randomized design (CRD) in which eight treatments were replicated six times with seven birds per replicate. A total of 336, one-day-old (COBB 500) chicks were fed with the eight treatment diets, which include T1 = negative control (Basal diet), T2 = positive control (Basal diet + 0.01% (w/w) Oxytetracycline), T3 = Basal diet + 0.2% (v/w) postbiotic TL1, T4 = Basal diet + 0.2% (v/w) postbiotic RS5, T5 = Basal diet + 0.2% (v/w) paraprobiotic RG11, T6 = Basal diet + 0.2% (v/w) postbiotic RI11, T7 = Basal diet + 0.2% (v/w) paraprobiotic RG14, T8 = Basal diet + 0.2% (v/w) paraprobiotic RI11, for 35 days in a closed house system. Results: The growth performance indicators (final body weight, cumulative weight gain, and feed conversion ratio) were not significantly (p > 0.05) affected by the dietary treatments. However, feed intake recorded a significant (p < 0.05) change in the starter and finisher phases across the dietary treatments. Paraprobiotic RG14 had significantly (p < 0.05) lower abdominal fat and intestines. Villi heights were significantly (p < 0.05) increased, while the crypt depth decreased significantly due to dietary treatments. The dietary treatments significantly influenced colon mucosa sIgA (p < 0.05). Similarly, plasma immunoglobulin IgM level recorded significant (p < 0.05) changes at the finisher phase. In this current study, the hepatic GHR and IGF-1 expressions were significantly (p < 0.05) increased by postbiotics and paraprobiotics supplementation. Conclusions: Therefore, it was concluded that postbiotics and paraprobiotics differ in their effect on broiler chickens. However, they can replace antibiotics without compromising the growth performance, carcass yield, and immune status of broiler chickens.

Nonpharmacological Treatment Strategies for the Management of Canine Chronic Inflammatory Enteropathy—A Narrative Review

Chronic inflammatory enteropathy (CIE) refers to a heterogeneous group of idiopathic diseases of the dog characterised by persistent gastrointestinal (GI) clinical signs. If conventional dietary treatment alone would be unsuccessful, management of CIE is traditionally attained by the use of pharmaceuticals, such as antibiotics and immunosuppressive drugs. While being rather effective, however, these drugs are endowed with side effects, which may impact negatively on the animal’s quality of life. Therefore, novel, safe and effective therapies for CIE are highly sought after. As gut microbiota imbalances are often associated with GI disorders, a compelling rationale exists for the use of nonpharmacological methods of microbial manipulation in CIE, such as faecal microbiota transplantation and administration of pre-, pro-, syn- and postbiotics. In addition to providing direct health benefits to the host via a gentle modulation of the intestinal microbiota composition and function, these treatments may also possess immunomodulatory and epithelial barrier-enhancing actions. Likewise, intestinal barrier integrity, along with mucosal inflammation, are deemed to be two chief therapeutic targets of mesenchymal stem cells and selected vegetable-derived bioactive compounds. Although pioneering studies have revealed encouraging findings regarding the use of novel treatment agents in CIE, a larger body of research is needed to address fully their mode of action, efficacy and safety.

The microbiota of healthy dogs demonstrates individualized responses to synbiotic supplementation in a randomized controlled trial

Background

Probiotics have been demonstrated to ameliorate clinical signs of gastrointestinal diseases in dogs in various studies. However, the effect of probiotics in a healthy population, as well as factors contributing individualized responses, remain largely unknown. This trial examined gut microbiota (GM) and health outcomes in household dogs after synbiotic (SN) supplementation containing probiotics and inulin (a prebiotic). Healthy dogs were randomized to receive SN (50 mg/d inulin and 20 billion total CFU/d of L. reuteri, P. acidilactici, E. faecium, L. acidophilus, B. animalis, L. fermentum, L. rhamnosus) or placebo (PL) for 4 weeks. Owners completed a health survey and collected stool samples for GM profiling (shotgun metagenomic sequencing) at baseline and week 4 in both groups, and at week 6 in the SN group.

Results

A significant shift (p < 0.001) in β-diversity was observed in the SN (n = 24), but not PL group (n = 19), at week 4 relative to baseline. Forty-five bacterial species, 43 (96%) of which were Lactobacillales, showed an increase in the relative abundances (≥2 fold change, adjusted p < 0.05) in the SN group at week 4. E. coli also decreased at week 4 in the SN group (2.8-fold, adjusted p < 0.01). The altered taxa largely returned to baseline at week 6. The degree of changes in β-diversity was associated with GM at baseline. Specifically, dogs with higher Proteobacteria and lower Lactobacillales responded more robustly to supplementation in terms of the change in β-diversity. Dogs fed SN tended to have lower diarrhea incidence (0% vs 16%, p = 0.08).

Conclusions

SN supplement had a short-term impact on the gut microbiota in healthy household dogs as characterized by shotgun metagenomic sequencing. Findings warrant further investigation with longer duration and populations at risk of gastrointestinal diseases. The magnitude of response to the supplement was associated with microbial profile at baseline. To our knowledge, this is the first study documenting such association and may provide a basis for personalized nutrition in companion dogs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42523-021-00098-0.

The Composition and Diversity of the Gut Microbiota in Children Is Modifiable by the Household Dogs: Impact of a Canine-Specific Probiotic

The development of the infant gut microbiota is initiated during pregnancy and continued through early life and childhood, guided by the immediate environment of the child. Our aim was to characterize the shared microbiota between dogs and children as well as to determine whether introduction to dogs of a dog-specific probiotic combination modifies the transfer process. We studied 31 children from allergic families with pet dog(s) and 18 control families without a dog. Altogether 37 dogs were randomized for a 4-week period in a double-blind design to receive canine-derived probiotic product containing a mixture of L. fermentum, L. plantarum, and L. rhamnosus, or placebo. Fecal samples from children and dogs were taken before and after the treatment. Distinctive gut microbiota composition was observed in children with dogs compared to those without a dog, characterized by higher abundance of Bacteroides and short-chain fatty acid producing bacteria such as Ruminococcus and Lachnospiraceae. Probiotic intervention in dogs had an impact on the composition of the gut microbiota in both dogs and children, characterized by a reduction in Bacteroides. We provide evidence for a direct effect of home environment and household pets on children microbiota and document that modification of dog microbiota by specific probiotics is reflected in children's microbiota.

Potential Pharmaceutical and Food Applications of Postbiotics: A Review

In recent decades, functional foods with ingredients comprising probiotics, prebiotics and postbiotics have been gaining a lot of attention from scientists. Probiotics and postbiotics are usually applied in pharmaceutical formulations and/or commercial food-based products. These bioactive agents can be associated with host eukaryotic cells and have a key role in maintaining and restoring host health. The review describes the concept of postbiotics, their quality control and potential applications in pharmaceutical formulations and commercial food-based products for health promotion, prevention of disease and complementary treatment. Despite the effectiveness of probiotic products, researchers have introduced the concept of postbiotic to optimize their beneficial effects as well as to meet the needs of consumers to provide a safe product. The finding of recent studies suggests that postbiotics might be appropriate alternative agents for live probiotic cells and can be applied in medical, veterinary and food practice to prevent and to treat some diseases, promote animal health status and develop functional foods. Presently scientific literature confirms that postbiotics, as potential alternative agents, may have superiority in terms of safety relative to their parent live cells, and due to their unique characteristics in terms of clinical, technological and economical aspects, can be applied as promising tools in the drug and food industry for developing health benefits, and therapeutic aims.

Potential in vivo delivery routes of postbiotics

Bioactive micro- and macro-molecules (postbiotics) derived from gut beneficial microbes are among natural chemical compounds with medical significance. Currently, a unique therapeutic strategy has been developed with an emphasis on the small molecular weight biomolecules that are made by the microbiome, which endow the host with several physiological health benefits. A large number of postbiotics have been characterized, which due to their unique pharmacokinetic properties in terms of controllable aspects of the dosage and various delivery routes, could be employed as promising medical tools since they exert both prevention and treatment strategies in the host. Nevertheless, there are still main challenges for the in vivo delivery of postbiotics. Currently, scientific literature confirms that targeted delivery systems based on nanoparticles, due to their appealing properties in terms of high biocompatibility, biodegradability, low toxicity, and significant capability to carry both hydrophobic and hydrophilic postbiotics, can be used as a novel and safe strategy for targeted delivery or/and release of postbiotics in various (oral, intradermal, and intravenous) in vivo models. The in vivo delivery of postbiotics are in their emerging phase and require massive investigation and randomized double-blind clinical trials if they are to be applied extensively as treatment strategies. This manuscript provides an overview of the various postbiotic metabolites derived from the gut beneficial microbes, their potential therapeutic activities, and recent progressions in the drug delivery field, as well as concisely giving an insight on the main in vivo delivery routes of postbiotics.

State-of-the-Art of the Nutritional Alternatives to the Use of Antibiotics in Humans and Monogastric Animals

Simple Summary

Antibiotic resistance represents a worldwide recognized issue affecting both human and veterinary medicine, with a particular focus being directed towards monogastric animals destined for human consumption. This scenario is the result of frequent utilization of the antibiotics either for therapeutic purposes (humans and animals) or as growth promoters (farmed animals). Therefore, the search for nutritional alternatives has progressively been the object of significant efforts by the scientific community. So far, probiotics, prebiotics and postbiotics are considered the most promising products, as they are capable of preventing or treating gastrointestinal diseases as well as restoring a eubiosis condition after antibiotic-induced dysbiosis development. This review provides an updated state-of-the-art of these nutritional alternatives in both humans and monogastric animals.

Abstract

In recent years, the indiscriminate use of antibiotics has been perpetrated across human medicine, animals destined for zootechnical productions and companion animals. Apart from increasing the resistance rate of numerous microorganisms and generating multi-drug resistance (MDR), the nonrational administration of antibiotics causes sudden changes in the structure of the intestinal microbiota such as dysbiotic phenomena that can have a great clinical significance for both humans and animals. The aim of this review is to describe the state-of-the-art of alternative therapies to the use of antibiotics and their effectiveness in humans and monogastric animals (poultry, pigs, fish, rabbits, dogs and cats). In particular, those molecules (probiotics, prebiotics and postbiotics) which have a direct function on the gastrointestinal health are herein critically analysed in the prevention or treatment of gastrointestinal diseases or dysbiosis induced by the consumption of antibiotics.

Efficacy of an orally administered anti-diarrheal probiotic paste (Pro-Kolin Advanced) in dogs with acute diarrhea: A randomized, placebo-controlled, double-blinded clinical study

BACKGROUND

Acute diarrhea is a common clinical presentation of dogs. The effect of specific anti-diarrheal probiotic pastes (ADPPs) in the management of acute, uncomplicated diarrhea in dogs is unknown.

HYPOTHESIS

Administration of an ADPP containing Enterococcus faecium 4b1707 will improve the clinical outcome of acute, uncomplicated diarrhea in dogs compared to placebo.

ANIMALS

One hundred forty-eight client-owned dogs with acute diarrhea as the main clinical sign.

METHODS

Double-blinded, placebo-controlled, randomized, blocked, multicenter clinical field study conducted at 14 primary care veterinary practices in the United Kingdom and Ireland.

RESULTS

The ADPP was associated with better clinical outcome compared to placebo in dogs with acute, uncomplicated diarrhea. Dogs in the ADPP group had a significantly shorter duration of diarrhea (ADPP: median, 32 hours; 95% confidence interval [CI], 2-118; n = 51; Placebo: median, 47 hours; 95% CI, 4-167; n = 58; P = .008) and the rate of resolution of diarrhea was 1.60 times faster in the ADPP group than in the Placebo group (ratio, 1.60; 95% CI, 1.08-2.44; P = .02). Fewer dogs required additional medical intervention (AMI) for non-improvement or worsening in the ADPP group compared to the Placebo group (3.5% of dogs and 14.8% of dogs, respectively), with a relative risk of 0.88 (P = .04; AMI, ADPP, 3.5%, 2/57 dogs; Placebo, 14.8%, 9/61 dogs; relative risk, 0.88; 95% CI, 0.77-0.99).

CONCLUSION AND CLINICAL IMPORTANCE

The ADPP may accelerate resolution of acute diarrhea in dogs and decrease the requirement for AMI.

Effects of oral Akkermansia muciniphila supplementation in healthy dogs following antimicrobial administration

OBJECTIVE To measure effects of oral Akkermansia muciniphila administration on systemic markers of gastrointestinal permeability and epithelial damage following antimicrobial administration in dogs. ANIMALS 8 healthy adult dogs. PROCEDURES Dogs were randomly assigned to receive either A muciniphila (10⁹ cells/kg; n = 4) or vehicle (PBS solution; 4) for 6 days following metronidazole administration (12.5 mg/kg, PO, q 12 h for 7 d). After a 20-day washout period, the same dogs received the alternate treatment. After another washout period, experiments were repeated with amoxicillin-clavulanate (13.5 mg/kg, PO, q 12 h) instead of metronidazole. Fecal consistency was scored, a quantitative real-time PCR assay for A muciniphila in feces was performed, and plasma concentrations of cytokeratin-18, lipopolysaccharide, and glucagon-like peptides were measured by ELISA before (T0) and after (T1) antimicrobial administration and after administration of A muciniphila or vehicle (T2). RESULTS A muciniphila was detected in feces in 7 of 8 dogs after A muciniphila treatment at T2 (3/4 experiments) but not at T0 or T1. After metronidazole administration, mean change in plasma cytokeratin-18 concentration from T1 to T2 was significantly lower with vehicle than with A muciniphila treatment (-0.27 vs 2.4 ng/mL). Mean cytokeratin-18 concentration was lower at T1 than at T0 with amoxicillin-clavulanate. No other significant biomarker concentration changes were detected. Probiotic administration was not associated with changes in fecal scores. No adverse effects were attributed to A muciniphila treatment. CONCLUSIONS AND CLINICAL RELEVANCE Detection of A muciniphila in feces suggested successful gastrointestinal transit following oral supplementation in dogs. Plasma cytokeratin-18 alterations suggested an effect on gastrointestinal epithelium. Further study is needed to investigate effects in dogs with naturally occurring gastrointestinal disease.

A canine-specific probiotic product in treating acute or intermittent diarrhea in dogs: A double-blind placebo-controlled efficacy study

A double-blind placebo-controlled intervention study on 60 dogs recruited from a pool of canine patients visiting a veterinary practice and diagnosed with acute diarrhea was conducted. The dogs received in randomized manner either a sour-milk product containing three canine-derived Lactobacillus sp. probiotics in combination of Lactobacillus fermentum VET 9A, L. rhamnosus VET 16A, and L. plantarum VET 14A (2×10⁹cfu/ml), or placebo. Stool consistency, general well-being, and the numbers of specific pathogens in stool samples were analyzed. Our results demonstrated that the treatment with the study sour-milk product had a normalizing effect on canine stool consistency. The treatment also enhanced the well-being of the pet by maintaining appetite and may reduce vomiting. In addition, the concentrations of Clostridium perfringens and Enterococcus faecium, which typically increase during diarrhea episodes in dogs, were decreased in probiotic group feces when compared with the placebo group. Taken together, the sour-milk with the specific probiotic combination had a normalizing effect on acute diarrhea in dogs which was associated with decreased numbers of potential pathogens in the feces of probiotic-treated dogs.

Microbiota and probiotics in canine and feline welfare

Dogs and cats have been cohabiting with us for thousands of years. They are the major human companions. Today, dogs and cats live in urban areas. Cats and most dogs are on high carbohydrate diets and face similar life-style challenges as the human beings. The health and well-being of companion animals, just as their owners, depends on the gut microbes. Providing a proper care and nutritionally balanced diet to companion animals is recognised as a part of our responsibility to maintain the health and well being of our pet. However, as microbiota differences may facilitate exposure to pathogens and harmful environmental influences, it is prudent to search for novel tools to protect dogs and cats and at the same time the human owners from pathogens. Specific probiotic strains and/or their defined combinations may be useful in the canine and feline nutrition, therapy, and care. Probiotic supplementations have been successful in the prevention and treatment of acute gastroenteritis, treatment of IBD, and prevention of allergy in companion animals. New challenges for probiotic applications include maintenance of obesity and overweight, urogenital tract infections, Helicobacter gastritis and parasitic infections. The probiotics of human origin appear to be among the new promising tools for the maintenance of pets' health. However, the host-derived microorganisms might be the most appropriate probiotic source. Therefore, more controlled trials are needed to characterise new and safe probiotic preparations with an impact on general health and well being as well as health maintenance in dogs and cats.