Conjugated linoleic acid (CLA) is a functional food ingredient with prebiotic properties that provides health benefits for various human pathologies and disorders. However, limited natural CLA sources in animals and plants have led microorganisms like Lactobacillus and Bifidobacterium to emerge as new CLA sources. Microbial conversion of linoleic acid to CLA is mediated by linoleic acid isomerase and multicomponent enzymatic systems, with CLA production efficiency dependent on microbial species and strains. Additionally, complex factors like LA concentration, growth status, culture substrates, precursor type, prebiotic additives, and co-cultured microbe identity strongly influence CLA production and isomer composition. This review summarizes advances in the past decade regarding microbial CLA production, including bacteria and fungi. We highlight CLA production and potential regulatory mechanisms and discuss using microorganisms to enhance CLA content and nutritional value of fermented products. We also identify primary microbial CLA production bottlenecks and provide strategies to address these challenges and enhance production through functional gene and enzyme mining and downstream processing. This review aims to provide a reference for microbial CLA production and broaden the understanding of the potential probiotic role of microbial CLA producers.

共轭亚油酸 (CLA) 是一种具有益生元特性的功能性食品成分，可为各种人类病理和疾病提供健康益处。然而，动物和植物中有限的天然 CLA 来源导致乳杆菌和双歧杆菌等微生物成为新的 CLA 来源。亚油酸向 CLA 的微生物转化是由亚油酸异构酶和多组分酶系统介导的，CLA 生产效率取决于微生物种类和菌株。此外，LA 浓度、生长状态、培养基质、前体类型、益生元添加剂和共培养微生物特性等复杂因素强烈影响 CLA 产量和异构体组成。本综述总结了过去十年有关微生物 CLA 生产（包括细菌和真菌）的进展。我们重点介绍 CLA 的生产和潜在的调控机制，并讨论利用微生物来提高发酵产品的 CLA 含量和营养价值。我们还确定了主要微生物 CLA 生产瓶颈，并提供应对这些挑战的策略，并通过功能基因和酶挖掘以及下游加工来提高产量。本综述旨在为微生物 CLA 生产提供参考，并加深对微生物 CLA 生产者潜在益生菌作用的理解。