Heterofermentative lactic acid bacteria (LAB) have the ability to metabolize 6-carbon sugars, such as galactose, to produce carbon dioxide, which can cause late-stage gas formation defects in Cheddar cheese characterized by slits, cracks, and blown retail packaging. Slits and cracks make the cheese more difficult to shred and slice, and blown bags make the cheese less appealing to customers. Homofermentative LAB are often used as adjunct cultures to modify the flavor of Cheddar cheese and have the potential to act as bioprotective cultures and inhibit gas production by heterofermentative nonstarter LAB (NSLAB). Cheddar cheese was manufactured using 4 previously identified galactose-positive and lactose-negative LAB (Lacticaseibacillus rhamnosus 20DK04, Lacticaseibacillus paracasei 20DK06, Pediococcus acidilactici 23F, and Latilactobacillus curvatus WSU1) as adjunct cultures along with a starter culture consisting of Streptococcus thermophilus and Lactococcus species. The day after cheesemaking, cheese blocks were comminuted and inoculated with known gas-producing NSLAB (Levilactobacillus brevis 277-1, Limosilactobacillus fermentum 305-1, Lentilactobacillus parabuchneri CC01, and Paucilactobacillus wasatchensis WDCO4). The inoculated cheeses were then repressed into blocks, cut into smaller pieces, packaged, vacuum sealed, and stored at 14°C for 16 wk. Starter LAB, adjunct LAB, and gas-producing NSLAB were enumerated at 1, 8, and 16 wk using a modified Petrifilm method. Loosening of the cheese packages was used as a nondestructive measure of gas production every week. Extent of gas production was Lev. brevis 277-1 >Paucilactobacilluswasatchensis WDC04 >Lentilactobacillus parabuchneri CC01 >Limosilactobacillus fermentum 305-1. Using an adjunct LAB had varying effects and could either increase or reduce gas production depending on the NSLAB. Gas production was inhibited by Latilactobacillus curvatus WSU1 and Pediococcus acidilactici 23F when the NSLAB was Levilactobacillus brevis 277-1 but was stimulated when the NSLAB was Paucilactobacillus wasatchensis WDC04. In contrast, Lacticaseibacillus rhamnosus 20DK04 and Lacticaseibacillus paracasei 20DK06 had little effect on gas production by Lev. brevis 277-1 but inhibited gas production by Paucilactobacillus wasatchensis WDC04. Gas production by Lentilactobacillus parabuchneri CC01 was most inhibited by Pediococcus acidilactici 23F. Thus, when considering use of a bioprotective LAB to reduce unwanted gas production in Cheddar cheese, it is essential to know the NSLAB bacteria that is causing the gas defects.