ALthough, we all avoid using antibiotics at all costs.... If you had to choose any brand to cary with you (just in case) or take with to overseas trip, then what would it be? I am talking about broad spectrum here, nothing specific.
Ok, maybe not "the best" but "least harmful and most helpful".
I'd get a Z-Pak. Yes, natural antibiotics are great. But if you're going to a remote village in a place wehre's there's NOTHING for you if you get very, very ill, then you'll want something stronger.
Z-Paks are simple and shelf-stable.
If needed, I go with some natural antibiotics. Oil of Oregano is great stuff, kills most bugs with a few drops. Garlic has to be mentioned as well, it's taken me out of the deep end more times than I can count.
I've got Azithromycin and Augmentin in my emergency kit for my purposes. But you really need to study up if you want to have antibiotics in your kit. Things like what bugs they're effective against, your allergies to them, resistance prevelance in your travel areas, etc. It's not as straightforward as you think, and my picks might not be good for you.
I'm with James and Sarah here (I thought this was more the spirit of the question). In this day and age, if you've got a bona fide bacterial infection you'll probably need an antibiotic to fight it. Can your own immunity -- supplemented with natural compounds with antibiotic effecs -- hack it? Maybe. But IMO, risking letting a bug take a real hold in your body is far more dangerous especially with all the superbugs out there these days.
So I would go for one of the super AB's like azithromycin -- shortest most potent course possible -- and then work to repopulate the good guys ASAP. Also, the once a day short course is far more likely to be adhered to which is key to total wipe out!
If you're going to take a conventional antibiotic, it's crucial that you take probiotics immediately afterwards, otherwise the antibiotic will wipe out your good bacteria http://www.sciencedaily.com/releases/2008/12/081217190443.htm. I read a study showing that people who took antibiotics but not probiotics had their good bacteria wiped out even a year later. This shuts down your immune system since your good bacteria and immune cells, most of which are in your gut, communicate with each other in order to keep the immune system in balance. Over the short term, it's probably better in a supplement, but over the long term it's better to have fermented foods and drinks. I would agree with these 4 natural antibiotics as the best and add oil of oregano as mentioned above http://thenewsilversolution.com/natural-antibiotics/. Look up the research on them, there's good evidence for all of them having potent antimicrobial properties. Of course, if you have a strong immune system your chances of getting an infection are substantially lower to begin with. I'm sure strengthening the immune system has been discussed in other posts here so check those out as well.
I don't think broad spectrum antibiotics could be considered safe at any instance. Thats why we do bacteriogram with kids, to be able to use specific antibiotic with narrow spectrum.
In any way, using 250mlx2 Kefir with antibiotics will reduce negative results and improve efficacy.
If you live reasonably close to a "travel clinic," it would be worth the investment to go for a consultation well in advance of your trip.
Some conditions, such as typhoid, yellow fever and hepatitis A, are preventable by vaccines.
Antibiotics are useless unless they are matched to the most common diseases and drug resistance patterns in your areas of expected travel.
If you're using a custom insect repellent brew, test it on yourself before you travel to determine (1) that it works and (2) that you don't have an adverse reaction to it.
Finally, if you're travelling to the tropics, the most important issue is malaria prevention. You need to find out whether malaria is a problem at your destination, and what are the resistance patterns of the local strains. Malaria prophylaxis needs to be started before you depart and continued after your return. Detailed information is available on the CDC Malaria Map page.