Stomach issues seem pretty obvious, right? You know you have them when your belly aches, and there's not typically much you can do besides wait it out.

Not so, says Dr. Armond G. Schwartz, director of gastroenterology at Methodist Dallas Medical Center. There are several sneaky symptoms that point to tummy troubles, or a catch-all that doctors call "leaky gut," and some may not be what you're expecting.

Here are a few things you should pay attention to, and always see your doctor if you suspect something more serious.

You're more forgetful
We all get a little foggy from time to time, but if you notice you're forgetting things more often, then the issue might be lower down.

"There are as many bacterial cells in our gut as there are human cells in our entire body," says Dr. Schwartz. "That's a one-to-one ratio of bacterial to human cells. These bacteria metabolize substances and the compounds produced may affect the gut-brain axis. They have been implicated with abnormalities in brain function, behavior, and brain disease."

Your sweet tooth is stronger
Find yourself craving more sugar than usual? That might be your body trying to tell you something. Gut bacteria secretes proteins called leptin and ghrelin that are similar to hunger-regulating hormones, which affect both our food cravings and mood. The more sugar you eat, the more that bacteria craves it, but addressing the root problem in your gut (and eradicating the excess bacteria) can stop the cycle.

"It is unknown, but I suspect that gut microbiome may direct one's diet to certain cravings," says Dr. Schwartz. "In theory if we can alter the gut microbiome to produce 'good bacteria,' we may be able to treat or prevent diseases."

You have bad breath
This one is hard to ignore. If you notice a funky smell each time you open your mouth, it might signal more than a lapse in oral hygiene. Bad breath, or halitosis, is caused by odor-inducing microbes that reside in between your teeth and gums. But like those sugar cravings, they exist when there's an imbalance in your overall digestive health.

"The diversity of our gut microbiome is incredibly important for maintaining not only the health of the GI system, but for our overall health as well," says Dr. Schwartz.

You're moodier than normal
Mental health is not isolated to only the brain. There's evidence to suggest that someone with mental health issues may not be able to absorb micronutrients properly, meaning that serotonin and dopamine — your feel-good hormones — aren't sticking around.

If any of this sounds familiar or you'd like to get your possible symptoms checked out, schedule an appointment with a physician that specializes in gastroenterology.