The present study was conducted with privately owned dogs and cats to investigate whether a relationship exists between the dietary AGEs and the urinary excretion of AGEs, as indication of possible effective absorption of those compounds in the intestinal tract of pet carnivores. For this purpose, data were collected from both raw fed and dry processed food (DPF) fed to dogs and cats, through spot urine sampling and questionnaires. Raw pet food (RF, low in AGE diets) was fed as a primary food source to 29 dogs and DPF to 28 dogs. Cats were categorized into 3 groups, which were RF (n = 15), DPF (n = 14) and dry and wet processed pet food (DWF, n = 25). Urinary‐free carboxymethyllysine (CML), carboxyethyllysine (CEL) and lysinoalanine (LAL) were analysed using ultrahigh‐performance liquid chromatography (UHPLC)—mass spectrometry, and were standardized for variable urine concentration by expressing the AGE concentrations as a ratio to urine creatinine (Ucr) concentration (µg/µmol Ucr). Urinary excretion of CML, CEL and LAL in dogs fed with DPF was 2.03, 2.14 and 3 times higher compared to dogs fed with RF (p < .005). Similar to the dogs, a significant difference in CML:Ucr, CEL:Ucr and LAL:Ucr between the three diet groups was observed in cats (p‐overall < 0.005, ANOVA), in which the RF fed group excreted less AGEs than the other groups. Linear regression coefficients and SE of CML:Ucr, CEL:Ucr and LAL:Ucr showed that body weight and neuter status were significantly correlated with CML and CEL excretion, but not to LAL excretion. Our results revealed a significant correlation between dietary AGEs and urinary excretion of free CML, CEL and LAL, and also showed that endogenous formation of these AGEs occurs in both dogs and cats under physiological conditions.

Background and Aim: The use of antibiotics is associated with many side effects, with the development of bacterial resistance being particularly important. It has been found that dogs and their owners host similar resistant bacteria. This contributes to increased concurrent bacterial resistance and a possible trend of increased bacterial resistance in humans. Thus, using probiotics in dogs is an alternative option for preventing and reducing the transmission of bacterial resistance from dogs to humans. Probiotics are characterized by their potential to endure low pH levels and high concentrations of bile acids in the gastrointestinal tract. Lactobacilli are more acid-tolerant and resistant to bile acid, so they are ideal probiotics to be added to the canine diet. According to the previous studies, the benefits of Lactobacillus are a stable nutritional status and greater digestibility, along with improved fecal scores and reduced ammonia in dogs. However, no studies have been conducted with Lactobacillus plantarum CM20-8 (TISTR 2676), Lactobacillus acidophilus Im10 (TISTR 2734), Lactobacillus rhamnosus L12-2 (TISTR 2716), Lactobacillus paracasei KT-5 (TISTR 2688), and Lactobacillus fermentum CM14-8 (TISTR 2720), or their use in combination. Hence, the aim of this study was to examine the possible effects of the aforementioned Lactobacillus on hematological indices, nutritional status, digestibility, enzyme activities, and immunity in dogs. From the results, a new and safe strain of Lactobacillus may emerge for use as a probiotic in the future. Materials and Methods: In this study, 35 dogs were allocated equally into seven groups: Group 1 received a basal diet (control), while Groups 2–7 received the same diet further supplemented with L. plantarum CM20-8 (TISTR 2676), L. acidophilus Im10 (TISTR 2734), L. rhamnosus L12-2 (TISTR 2716), L. paracasei KT-5 (TISTR 2688), L. fermentum CM14-8 (TISTR 2720), or a mixture of probiotics (L. plantarum, L. acidophilus, L. rhamnosus, L. paracasei, and L. fermentum), respectively. All probiotics were administered at a dose of 109 colony-forming unit/dog for 28 days. Nutritional status, hematology, serum biochemistry, digestibility, enzyme activities, and immunity parameters were assessed. Results: There were no differences among the groups in body weight, feed intake, body condition score, fecal score, and fecal dry matter on the different sampling days. The hematology and serum biochemical analyses showed a difference only in creatinine activity (p < 0.001), with higher values in group L. fermentum CM14-8 (TISTR 2720) and lower values in group L. paracasei KT-5 (TISTR 2688) than in controls. However, all measurements were within the normal laboratory reference ranges. Fecal characteristics (fecal ammonia and fecal pH), fecal digestive enzyme activities, serum immunoglobulin (IgG), and fecal IgA did not differ significantly among the groups (p > 0.05). Conclusion: Lactobacillus plantarum CM20-8 (TISTR 2676), L. acidophilus Im10 (TISTR 2734), L. rhamnosus L12-2 (TISTR 2716), L. paracasei KT-5 (TISTR 2688), and L. fermentum CM14-8 (TISTR 2720), along with their mixture are safe and non-pathogenic additives for use as new probiotic strains of Lactobacillus in dogs. Although the new Lactobacillus strains had no effect on hematology, serum biochemistry, nutritional status, digestive enzyme activities, immunity, body weight, feed intake, or body condition scores in dogs, further studies should investigate the intestinal microbiota and the development of clinical treatments. Keywords: digestibility, Lactobacillus, nutritional status, probiotics.

The aquatic plant Wolffia globosa and the probiotic Limosilactobacillus reuteri KUB-AC5 have been proposed as candidate synbiotic components targeting gut microbiota modulation. In this study, we investigated the effects of W. globosa supplementation, alone or in combination with L. reuteri KUB-AC5, on the gut microbiota and health status in healthy adult dogs. For a 28-day feeding trial, 24 healthy dogs were randomly assigned to three dietary treatment groups: control, prebiotic (PRE; 3.5% W. globosa powder), and synbiotic (SYN, 3.5% W. globosa powder combined with L. reuteri KUB-AC5 at 1 × 10⁸ CFU/day). No significant differences were observed in body weight, body condition score, fecal consistency, feed intake, or blood parameters among groups (p > 0.05). Although overall gut microbial diversity remained unchanged, linear discriminant analysis effect size analysis revealed the selective enrichment of specific bacterial taxa. The PRE group exhibited higher relative abundances of Parabacteroides merdae, Romboutsia lituseburensis, Subdoligranulum variabile, and Phocaeicola sartorii, whereas the SYN group showed increased levels of Escherichia coli and Terrisporobacter glycolicus and reduced levels of Anaerobiospirillum succiniciproducens and Campylobacter upsaliensis (p < 0.05). In conclusion, W. globosa, alone or combined with L. reuteri KUB-AC5, was safely used to modulate gut bacterial composition as a potential functional ingredient.

Probiotics, particularly Lactobacillus spp., play a key role in supporting host health by modulating the gut and oral microbiota, enhancing immune responses, and maintaining microbial balance. While microbial diversity and composition are crucial for gastrointestinal and oral health, the impact of new Lactobacillus strains on healthy dogs has not been fully explored. This study evaluated the impact of new Lactobacillus strains on the gut and oral microbiota of healthy dogs. A sample of 35 adult dogs was divided into seven groups. Group 1 received a basal diet, while Groups 2–6 received individual Lactobacillus strain supplements: L. plantarum CM20-8 (TISTR 2676), L. acidophilus Im10 (TISTR 2734), L. rhamnosus L12-2 (TISTR 2716), L. paracasei KT-5 (TISTR 2688), and L. fermentum CM14-8 (TISTR 2720), respectively. Group 7 received a mixed probiotic supplement containing all five strains. Each dog received the respective L. strain at 10⁹ CFU/day. Fecal and oral microbiota were analyzed using 16S rRNA sequencing. Based on the results, probiotic supplementation did not significantly change the overall microbial diversity. Dogs supplemented with L. fermentum CM14-8 (TISTR 2720) had a significantly (p=0.02) higher abundance (1.97%) of the beneficial genus Faecalibacterium in fecal samples than the control group (0.64%). In oral microbiota, compared to the control group, there were significant (p=0.03) reductions in the abundance of the Desulfobacterota in dogs receiving L. acidophilus Im10 (2.19%), L. rhamnosus L12-2 (2.32%), L. paracasei KT-5 (2.59%), L. fermentum CM14-8 (2.11%), and the mixed probiotic (2.69%). These findings highlighted the potential of specific probiotic strains, especially L. fermentum CM14-8, to modulate oral and gut microbiota in healthy dogs. Further studies are essential in clinical populations and functional assessments to define their preventive and therapeutic applications.