Friday Q&A: GLP-1s & metabolism; antibiotics & the gut microbiome; finding a new doctor; & electrolyte water
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ICYMI 👉
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The following questions have been lightly edited for length and clarity.
QUESTION #1: GLP-1S & METABOLISM
Dr. McBride, I've been on semaglutide for two years and it's worked! I've lost weight, my blood sugar is better, and my doctor is pleased. But I've started wondering about the longer-term picture. If I'm on this medication for years, or possibly the rest of my life, what is it actually doing to my metabolism over time?
-Carrie
Dear Carrie,
I get this question a lot, and it’s a good one. First, some reassurance: GLP-1 receptor agonists aren’t new. The first one was approved around 2005, which means we have nearly two decades of real-world data on this drug class. Semaglutide works by mimicking the GLP-1 hormone your body already makes, slowing gastric emptying, reducing appetite signaling in the brain, and improving insulin sensitivity. This isn’t chemically rewiring your metabolism the way stimulant-based diet drugs of the past did.
Am I worried about long-term harm from a well-studied medication that has clearly improved your metabolic markers? No, especially when we know a lot about the harm caused by the alternative: sustained metabolic dysfunction, chronic inflammation, elevated blood sugar, and the cascade of cardiovascular and liver disease that follows. The risks of those things are not theoretical. They’re well documented.
Can people regain weight after stopping? Yes. But the patients who fare best are the ones who use the medication not only to lose weight, but to rebuild trust with their body, gain insight into their relationship with food, change actual behaviors around eating and movement. The medication can quiet the noise. It can’t do that underlying work for you.
So, I suggest changing the question you to bring to your next appointment from “Should I be scared of staying on this?” to “Am I using the breathing room this drug is giving me as strategically as possible?”
P.S. That’s the kind of reframing I write about in my book, Beyond the Prescription!
QUESTION #2: ANTIBIOTICS & GUT MICROBIOME
Hi Dr. McBride! I recently read an article about how antibiotics disrupt the gut microbiome, and my doctor just gave me an antibiotic for a sinus infection. The piece made it sound like a single course of antibiotics can cause lasting damage to gut bacteria. Is this something I should consider before starting (I think it is amoxicillin)?
- Layla
Dear Layla,
Yes, antibiotics disrupt the gut microbiome. That’s real. A course of antibiotics can reduce microbial diversity, sometimes for weeks, occasionally longer. But for most healthy people, the microbiome is remarkably resilient, and it recovers over time. The dramatic headlines about permanent damage are not well supported by evidence in otherwise healthy adults taking a standard short course of antibiotics for a routine infection.
The more important question is whether you actually need the antibiotics. Sinus infections are frequently viral, in which case antibiotics do nothing except contribute to resistance and, yes, gut disruption for no benefit. If your doctor has assessed that yours is bacterial (based on your symptoms, their duration, and clinical judgment), then the calculus shifts. The risk of an untreated bacterial infection outweighs the temporary hit to your microbiome. If you’re uncertain whether the prescription is truly warranted, it’s reasonable to ask your doctor directly: is this definitely bacterial, or are we treating it just in case?
If you do take them, there are a few things worth doing. Eat plenty of fiber-rich foods and fermented foods like yogurt and kefir during and after the course. These support the beneficial bacteria your gut needs to repopulate. A probiotic during and after a course of antibiotics is one of the few times I routinely recommend one, as there’s reasonable evidence it helps ease the disruption and speed recovery. (You can watch my video for more tips on caring for your gut here!)
Trust your doctor's judgment here, and ask the question if you have doubts. That's exactly the right way to approach it. Good luck!
QUESTION #3: FINDING A NEW DOCTOR
I have recently moved to a new city. How do I find a doctor who is willing to spend time, to know me and my health, to have those nuanced conversations and serve as a guide rather than just a dispenser of medications like you suggest?
-Alison
Hi Alison,
What you’re describing—a doctor who knows you, thinks with you, and sees the whole picture—is what primary care is supposed to be. The hard truth is that the system has made it genuinely difficult to find, not because good doctors don’t exist, but because the incentive structure pushes them toward volume over relationship. It’s the central problem I wrote my forthcoming book, Beyond the Prescription (you can pre-order it here!) to address, because finding that kind of care, and knowing how to advocate for yourself when you can’t, is something every patient deserves a roadmap for.
That said, there are real ways to improve your odds. Start by asking around with your neighbors, colleagues, or any specialists you see. Word of mouth still surfaces the doctors who practice the way you’re describing better than any online review system, which is too easily gamed in both directions. When you have a name, call the office before booking and ask how long a new patient appointment runs. The answer tells you a lot.
It’s also worth looking into direct primary care practices in your area. The DPC model (where patients pay a monthly membership fee directly to the physician, bypassing insurance billing) exists precisely to create the kind of relationship you’re after: longer appointments, easier access, a doctor who actually has time to think. It can be expensive, but for many people it’s worth the investment and piece of mind.
When you do meet someone new, pay attention to whether they ask about your life, not just your symptoms, whether they tell you what they don’t know, and whether they seem genuinely curious about you as a person. Those qualities aren’t credentials and you won’t find them on a hospital website, but they’re what you’re actually looking for. It may take more than one try, and that’s okay.
QUESTION #4: ELECTROLYTE WATER
I’m physically active and in my 70s, and I’ve been trying to dial in my hydration. I keep seeing ads for drink mixes and electrolytes. A lot of them are packed with sweeteners, artificial flavors, or acidic ingredients that trigger my reflux. Is water not enough anymore? What’s worth trying?
-Maryanne
Hello Maryanne,
Regular water is usually enough! However it’s important to know that the sensation of thirst becomes less reliable as we get older, which means you can be meaningfully dehydrated before your body signals it. And if you’re sweating regularly during exercise, you’re losing electrolytes—primarily sodium—that plain water doesn’t replace.
The good news is that you don’t need a specially formulated product to address this. Making sure you’re eating enough sodium, potassium, and magnesium through food is the unglamorous but genuinely effective starting point, and most people eating a reasonably varied diet already are. A small pinch of salt in a glass of water before or after exercise does the job without the additives that bother you.
The marketing around hydration products has gotten wildly out of hand! Most of what’s being sold is unnecessary for the average active adult, and the ingredient lists you’re reading—sweeteners, citric acid, artificial flavoring—exist because plain electrolyte water doesn’t taste like much and doesn’t sell as well. That’s a commercial problem, not a medical one.
If you want something beyond plain water, coconut water in modest amounts provides natural electrolytes without the additives, though it does contain natural sugar worth keeping in mind. Some people also tolerate a small amount of diluted tart cherry juice well, which has the added benefit of modest anti-inflammatory properties relevant to exercise recovery.
But honestly? Consistent plain water intake throughout the day, plus paying attention to how you feel, will take you further than most products on the market. Stay well!
Pre-order Beyond the Prescription — out August 11!
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