Abstract: To systematically evaluate the quality status of commercially available pet food probiotic products， this study conducted analyses from multiple perspectives，including strain compliance，accuracy of stated viable counts，strain stability，and gastric fluid tolerance. The objective was to provide a scientific basis for the establishment of industry standards and the enhancement of product quality. Forty -four commercially available products were collected. Strain compliance was assessed against the“Catalogue of Microorganisms Permitted for Use in Feed”. Viable counts were determined using the plate count method. Strain identification was performed via MALDI-TOF MS. Storage survival and digestive survival rates were evaluated through accelerated stability testing and in vitro simulated gastric fluid testing. The findings revealed that some products utilized strains，such as Clostridium butyricum，not currently listed in the aforementioned catalogue. Over 75% of samples had significantly lower viable counts than the labeled values. Strain identification consistency was poor，with the actual detection frequency being only 50% of that indicated on the labels. Significant differences were observed among strains：Bacillus licheniformis demonstrated high storage stability and gastric fluid tolerance；Lactobacillus plantarum declined rapidly and exhibited extremely low gastric fluid tolerance（<0.3%）；Saccharomyces cerevisiae showed low storage stability，although some samples displayed relatively high gastric fluid tolerance. Quality issues prevalent in current commercial products include non- compliant strain usage，inflated viable count claims，and deficiencies in strain authenticity and stability. This multi- dimensional study reveals key quality defects in this sector，providing data to support the development of relevant industry standards，optimization of production processes，and informed consumer choices.

Key words: Pet food；probiotics；Compliance analysis；Strain Compliance；Gastric fluid tolerance；Shelf-life stability

摘要： 为系统评估市售宠物食品益生菌产品的质量现状，该研究从菌种合规性、活菌数真 实性、菌株稳定性及胃液耐受性等方面进行分析，以期为行业规范建立与产品质量提升提供科 学依据。收集44款市售产品，参照《可用于饲料的微生物目录》评估菌种合规性；采用平板计 数法测定活菌数；通过MALDI??TOF MS进行菌种鉴定；通过加速稳定性试验与体外模拟胃液试 验评估储存及消化存活率。部分产品使用丁酸梭菌等尚未列入《可用于饲料的微生物目录》的 菌种；超75%样品实测活菌数显著低于标示值；菌种鉴定一致性较差，实际鉴定频次仅为标签 标示的50%。不同菌种差异显著：地衣芽孢杆菌表现出较高的储存稳定性与胃液耐受性；植物 乳杆菌衰减迅速且胃液耐受性极低（<0.3%）；酿酒酵母储存稳定性较低，但部分样品胃液耐受 性较高。当前市售产品普遍存在菌种使用不规范、活菌数“虚标”、菌种真实性不足与稳定性差 等质量问题。该研究多维度揭示了该领域的关键质量缺陷，为相关行业标准制定、生产工艺优 化及理性消费提供了数据支持。

关键词: 宠物食品；益生菌；菌种合规性；质量评估；胃液耐受性；货架期稳定性