Progress towards butyrate-producing pharmabiotics: Butyricicoccus pullicaecorum capsule and efficacy in TNBS models in comparison with therapeutics

We read with interest the commentary of Philippe Marteau1 on our study2 in which the author rightly questions the therapeutic value of butyrate-producing bacteria as pharmabiotics in humans because of their difficulty to grow in vitro. While indeed lactic acid bacteria are easy to grow but seem to have limited efficacy, the butyrate-producing bacteria from Clostridium cluster IV and XIVa are promising candidates as pharmabiotics, provided that the strains can be cultured and formulated in a stable way. Butyricicoccus pullicaecorum easily grows under anaerobic conditions in M2GSC medium reaching 108 cfu/mL after 24 h incubation. Our group further evaluated the survival and viability of B pullicaecorum in hydroxypropylmethylcellulose (HPMC) capsules after they were anaerobically lyophilised in horse serum supplemented with 7.5% trehalose and 1 mg/mL cysteine HCl and only observed a reduction of 1 log after 7 months. Now, after 15 months of storage at 4°C, still 107 …