Method for reducing the likelihood of developing bladder or colorectal cancer in an individual human being

A method for treating an individual suffering from one of bladder cancer and colorectal cancer, comprising,

• providing in the gut of an individual a population of beneficial bacteria selected from the group consisting of Lactobacillus species;
• administering at least 6 grams per day of fiber to the individual to maintain a therapeutically effective amount of the beneficial bacteria in the gut of the individual human being;
• increasing the levels of at least one of Faecalibacterium prausnitzii, Bifidobacterium, Lachnospira, Veillonella, Coprococcus, Akkermansia muciniphila and Rothia in the individual's gut microbiome,
• administering to the individual an immune checkpoint inhibitor, and, using a clustered regularly interspaced short palindromic repeats (CRISPR) CRISPR associated protein (Cas) system or a CRISPR from Prevotella and Francisella 1(Cpf1) system, reducing the population of a second bacteria in the individual, said second bacteria selected from the group consisting of Staphylococcus aureus;
• Pseudomonas aeruginosa ;
• Klebsiella;
• Streptoccocus;
• Salmonella;
• Shigella;
• Mycobacterium tuberculosis;
• Enterococcus;
• Escherichia coli;
• Clostridium;
• Neisseria gonnorrhoea;
• Acinetobacter baumannii;
• and Campylobacter.