"B. subtilis" spores can survive the extreme heat during cooking. Some "B. subtilis" strains are responsible for causing ropiness or rope spoilage – a sticky, stringy consistency caused by bacterial production of long-chain polysaccharides – in spoiled bread dough and baked goods. For a long time, bread ropiness was associated uniquely with "B. subtilis" species by biochemical tests. Molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater "Bacillus" species variety in ropy breads, which all seems to have a positive amylase activity and high heat resistance. "B. subtilis" CU1 (2 × 109 spores per day) was evaluated in a 16-week study (10 days administration of probiotic, followed by 18 days wash-out period per each month; repeated same procedure for total 4 months) to healthy subjects. "B. subtilis" CU1 was found to be safe and well tolerated in the subjects without any side effects.