Can you restore your gut microbiome after a course of antibiotics?
Your gut microbiome partially recovers after a course of antibiotics, but a full return to its original state is rarely achieved. Probiotics do not demonstrably help with this; give your body time and discuss with your doctor whether a course of antibiotics is truly necessary.
Antibiotics cause major damage to the gut microbiome. Ciprofloxacin significantly reduces diversity within just three to four days. With a heavier combination of three broad-spectrum antibiotics, potentially harmful bacterial species temporarily disappear in the immediate aftermath, but at the same time beneficial species such as bifidobacteria and butyrate-producing bacteria decline sharply.
Recovery does occur, but is rarely complete. After a course of ciprofloxacin, the composition of the gut microbiome in all study participants still differed from its baseline ten months later. After the heavier triple course, the microbiome had largely returned after six weeks, but nine species that had been present in everyone before the course were still undetectable in most participants after six months. How much you recover varies considerably: there is no single recovery pattern, and even in the same person a second course plays out differently from the first.
Taking probiotics after a course of antibiotics sounds logical, but the opposite has been shown. Compared with people who took nothing extra, gut microbiome recovery in the gut lining was actually slower and incomplete in the group that took probiotics (a multi-strain product). Probiotics can reduce antibiotic-associated diarrhoea, but that is separate from actual restoration of the microbiome.
The fastest and most complete return was achieved with an autologous faecal transplant: stool that a person had frozen before the course and then had reintroduced afterwards. Within a few days the microbiome was almost entirely back, clearly faster than spontaneous recovery or recovery with probiotics. However, this is not a method that is readily available or applicable to everyone; it has so far been studied in a small group of participants.
Based on three human studies, including a small study in three individuals (ciprofloxacin, PMID 20847294), a study in 12 healthy young men (PMID 30349083), and a study with three groups receiving probiotics, an autologous faecal transplant, or nothing (PMID 30193113). All findings were obtained in humans, but the groups are small. No meta-analyses are available in this set.
Can you permanently change your gut microbiome through diet?
Diet does indeed change your gut microbiome, but lasting change requires lasting adjustment of your dietary pattern; a temporary diet has only a temporary effect.
Can you improve your gut bacteria by picking up microbes while playing outside?
Spending time regularly outdoors in green or natural environments increases the diversity of your gut bacteria. Even an hour or two a day in a park shows a measurable difference, though the evidence is still preliminary.
Can your gut microbiome influence inflammation in your body?
Your gut microbiome can influence inflammatory processes throughout your body via the gut wall. Eating more fibre and exercising regularly are the most well-supported ways to influence this favourably.
Can exercise improve your gut microbiome?
Moderate regular exercise demonstrably improves your gut microbiome, but you need to keep exercising because the effect disappears when you stop. Do not overdo it: very intensive training can actually put gut health under pressure.
Can your gut microbiome influence how long you live?
There are clear indications that the composition of your gut microbiome is associated with how long and how healthily you age, but whether modifying your microbiome extends your life has not yet been demonstrated in humans.
Can your gut microbiome affect your memory and concentration?
Your gut microbiome can influence your memory and concentration through several routes, but most of the evidence still comes from animal and laboratory research. What you can concretely do right now is support your gut health through diet, as direct supplementation or probiotics for cognition have not yet been sufficiently proven in humans.