Cheese-Ripening Bacteria May Also Benefit Gut Health, Study Finds

Scientists at the University of Reading have identified the bacteria responsible for the distinctive flavors of three British artisan cheeses, and found that some of the same microbes may offer benefits for gut health. The study, published in ACS Food Science & Technology, tracked microbial and chemical changes as the cheeses — made by Nettlebed Creamery in Oxfordshire — matured.

The researchers, led by PhD researcher Sabrina Longley of the university's Department of Food and Nutritional Sciences, studied a soft white-rind cheese aged just over a week, a washed-rind semi-soft cheese matured over several weeks, and a semi-hard cheese aged in hay for about nine months. All three contained bacteria with recognized probiotic potential. Streptococcus thermophilus, also used as a yogurt starter, dominated the semi-soft and harder cheeses throughout ageing, while Lactococcus lactis was present in all three from start to finish. The washed-rind and hay-aged cheeses also contained Propionibacterium freudenreichii, which produces propionic acid, a compound linked to anti-inflammatory effects, reduced cholesterol synthesis and appetite regulation.

The white mold Penicillium candidum, which forms the rind on the soft cheese, produces chitin, a dietary fiber that may act as a prebiotic, feeding beneficial gut bacteria. Hay ageing had a marked effect on the harder cheese's bacterial diversity: the fully matured cheese contained nearly four times as many bacterial species as it did earlier in the ageing process.

The researchers also found that lactose, the milk sugar many people struggle to digest, was almost entirely broken down by lactic acid bacteria and absent from all three cheeses by the time they were ready to eat. The team said further dietary intervention trials are needed to determine how these bacteria behave in the human gut after the cheese is eaten.