Collaborating with a team from the University of Gothenburg in Sweden, further findings of the colon-cancer (CRC) associated microbiota in question reveal an increase of bacteria known to produce butyrate.
This short-chain fatty acid is associated with anti-inflammatory benefits as well as colon health. However, more recently, it has also been shown to suppress colon cancer cell growth.
“Colorectal cancer (CRC) is one of the top three cancers diagnosed globally each year, and the risk of colorectal cancer is strongly correlated to lifestyle factors such as diet,” said Dr Ashley Hibberd, research and development scientist at DuPont Nutrition & Health.
“The results of our study show that the risk component from diet may be mediated by the microbiota, and that the specific probiotic strains used in this study have the potential to support the microbiota in a beneficial way.”
CRC currently affects approximately 1.4 million people each year and its incidence is increasing worldwide.
Evidence points to a link between lifestyle factors such as high consumption of red and processed meat and the risk of developing CRC.
Little is known about how the composition of the microbiota affects development of CRC, leading the research team to hypothesise that CRC risk and diet is overseen by the gut microbiota.
In the study, biopsy samples were taken from 15 patients with colon cancer of which eight of these patients received two daily tablets (ProBion) totalling 1.4×1010 colony forming units (CFUs) Bifidobacterium lactis Bl-04 and 7×109 CFUs Lactobacillus acidophilus NCFM.
These strains were chosen for this study because NCFM was previously shown to suppress colonic tumour growth in mice and reduce the level of carcinogenic metabolites in the human intestine.
Additionally, Bl-04 has been shown to have immunomodulation properties.
Faecal samples were then obtained from these patients after a colonoscopy was performed at the start of the study and during surgery.
In addition, 21 mucosal biopsies from non-cancer controls were obtained during the colonoscopy procedure followed by later faecal samples.
Results showed the microbiota from CRC patients was characterised by increased microbial diversity of Fusobacterium, Selenomonas and Peptostreptococcus species compared with the control microbiota.
Patients with colon cancer that received probiotics had an increased numbers of butyrate-producing bacteria, especially Faecalibacterium and Clostridiales spp in the tumour, non-tumour mucosa and faecal microbiota.
CRC-associated genera such as Fusobacterium and Peptostreptococcus tended to be reduced in the faecal microbiota of patients that received probiotics.
‘Strains show promise’
“The CRC-associated microbiota is being continuously defined as new biomarkers of CRC are discovered,” said Dr Yvonne Wettergren, Sahlgrenska Academy researcher based at the University of Gothenburg.
“The microbial dysbiosis observed in patients with CRC may be manipulated by probiotic bacteria if protected by the ProBion matrix, and the probiotic strains used in this study show promise as a beneficial component of enhancing the microbiome in CRC.”
The study spoke of future implications as a result of these findings commenting that the microbial dysbiosis observed in patients with CRC may be manipulated by probiotic bacteria.
“The probiotic strains used in this study showed much promise as a beneficial component of treatment and therapeutic development in CRC.
“Further studies should be conducted in a larger population to confirm these initial findings, and ideally should be complemented with metabolomics data to elucidate the role of butyrate.”
Source: BMJ Open Gastroenterology
Published online ahead of print: doi.org/10.1136/bmjgast-2017-000145
“Intestinal microbiota is altered in patients with colon cancer and modified by probiotic intervention.”
Authors: Ashley Hibberd et al.