1-Deoxynojirimycin (1-DNJ), a polyhydroxylated alkaloid piperidine compound, is naturally produced by plants, insects, and bacteria. While 1-DNJ is known for its anti-diabetic effects, it has recently been used as a therapeutic agent for antiobesity, anti-inflammatory, and anti-cancer activities, as well as for cosmetic applications, such as anti-aging. We focused our review on 1-DNJ produced by bacteria that are amenable to industrial utilization. We organized the 1-DNJ-producing bacteria into Bacillus subtilis, Bacillus amyloliquefaciens, other Bacillus species, and Streptomyces species and compared the optimal culture conditions for enhancing 1-DNJ production in each strain. We investigated studies on established 1-DNJ biosynthetic pathways and genes in Bacillus and Streptomyces species and introduced metabolic engineering to enhance 1-DNJ production using 1-DNJ biosynthetic genes. We also introduced methods for the qualitative and quantitative detection of 1-DNJ, as well as the biological functions and potential applications of 1-DNJ produced by bacteria.